Contents

• Introduction
• Bilateral Issues and Congress's Role
• Outlook
• Domestic Issues
• Political Developments Under Erdogan's Rule
• Economic Issues
• Selected Foreign Policy and Defense Issues
• U.S./NATO Strategic Relationship and Military Presence
• U.S.-Turkey Defense Cooperation (F-16s, F-35s, and Sanctions)
• Syria and Regional Implications (Kurds, U.S. Forces, Israel, and Iran)
• Israel and the Palestinians (Including Hamas)
• Russia and Ukraine
• Other Regional Relationships

Summary

U.S. relations with Turkey (Türkiye), a North Atlantic Treaty Organization (NATO) ally, have alternated between close cooperation and notable division. Turkey and other "global swing states" such as Saudi Arabia and India seek advantages in a global system with intensifying great-power competition. While Turkey's NATO membership is important for its security and the European Union (EU) is Turkey's largest trading partner and foreign investor, Turkey reportedly seeks to join the BRICS (Brazil, Russia, India, the People's Republic of China [PRC], South Africa) group and the PRC- and Russia-led Shanghai Cooperation Organization as well.

Over the past decade, the United States and Turkey have differed sharply on some major issues, including the U.S. partnership with Kurdish-led Syrian Democratic Forces (SDF) against the Islamic State organization, Turkey's 2019 procurement of a Russian S-400 surface-to-air defense system, and U.S. actions in response to the acquisition (suspending a sale of F-35 fighter aircraft to Turkey and imposing sanctions). These U.S.-Turkey rifts may have diminished to some extent given U.S. and Turkish efforts to (1) strengthen NATO and Ukraine since Russia's 2022 invasion of Ukraine, and (2) work with a new, generally pro-Turkish, Sunni Arab-led interim government in Syria after the 2024 fall of Bashar Al Asad.

Members of Congress may consider legislative and oversight options regarding Turkey, including on possible arms sales and how to address existing sanctions and legislative conditions. For example, U.S. legislation currently prohibits the transfer of F-35s to Turkey unless Turkey no longer possesses the Russian-origin S-400 system (or other associated items). President Donald Trump has reportedly expressed openness to an F-35 sale to Turkey if the S-400 is rendered inoperable, such as if the system were to be partially dismantled or moved to a U.S.-controlled base in Turkey. Amid heightened efforts to strengthen NATO and Ukraine since 2022, Congress has not blocked the advancement of possible U.S. sales of upgraded F-16 fighter aircraft or advanced munitions to Turkey, though some Members support restrictions or limitations on those proposed sales or other potential U.S.-Turkey defense transactions. A sale of F-35s to Turkey could decrease any relative military advantages that other countries possessing or seeking to acquire F-35s (including Israel and Greece) might have.

Developments in Syria, which are fluid, have relevance for U.S.-Turkey relations. The May 2025 decision by the Kurdistan Workers' Party (PKK) to end more than four decades of armed struggle against the Turkish government may potentially resolve some of Turkey's differences with the PKK-linked SDF. Turkey may be the most influential foreign power today in Syria, as the transitional government confronts challenges of military integration, the extension of government authority, and sectarian conflict; both Turkey and Syria's interim government oppose Kurdish autonomy Turkey-Israel tensions have increased as the two countries vie for influence in Syria—further straining relations that were already worsened by Turkey-Israel differences over (1) Turkey's continuing support for the Palestinian Sunni Islamist group Hamas after its October 2023 attacks and hostage-taking in Israel, (2) Israel's conduct of the war in Gaza, and (3) Turkey's official suspension of goods trade with Israel.

Additionally, domestic issues in Turkey could affect the trajectory of U.S.-Turkey relations. After the steady consolidation of power by President Recep Tayyip Erdogan and his Islamist-leaning Justice and Development Party over 22 years of ruling Turkey, in 2025 Erdogan's government has taken arguably its strongest actions to date against Turkey's main opposition Republican People's Party. Those moves include the imprisonment of Istanbul mayor Ekrem Imamoglu, perhaps the most serious rival Erdogan has faced in national leadership polls. Some observers speculate that Erdogan might be seeking to divide, demoralize, or disqualify the political opposition in Turkey in ways that could further consolidate or prolong his rule. Turkey also faces some economic challenges, including official annual inflation of over 30%.

As major developments evolve, Turkey reportedly seeks the following from the United States:

• Purchases of advanced fighter aircraft—F-16s and possibly fifth-generation F-35s—and the removal of defense-related U.S. sanctions imposed in 2020.
• Support in Syria for a transition from Kurdish-led SDF forces controlling key areas of northeast Syria and countering the Islamic State, to an arrangement in which Sunni Arab-led Syrian government forces take over these functions with backing from Turkey and other neighboring states.
• Acceptance and encouragement of a larger Turkish role in surrounding regions.

Analysts debate whether potential strategic and economic advantages from U.S. partnership with Turkey should incline the Trump Administration and Congress toward greater engagement, or whether Turkey's hedging behavior, policies on regional issues, or domestic controversies should give U.S. policymakers and lawmakers pause on closer cooperation.

Introduction

Bilateral Issues and Congress's Role

This report provides background information and analysis on key issues affecting U.S.-Turkey (Türkiye)¹ relations, including domestic Turkish developments and various foreign policy and defense matters. U.S. relations with Turkey, a member of the North Atlantic Treaty Organization (NATO) since 1952, have been complex, alternating between close cooperation and notable division or tension. The United States has valued Turkey's geopolitical importance to and military strength within the NATO alliance, as its second-largest military force, while viewing Turkey's NATO membership as helping anchor Turkey to the West.² Yet, over the past decade, the United States and Turkey have differed sharply on some major issues, particularly:

• Turkey's 2019 acquisition of an S-400 surface-to-air defense system from Russia, and the U.S. measures in response (suspending some major arms sales and placing sanctions on Turkey, discussed below).
• The U.S. military's partnership with the Kurdish-led Syrian Democratic Forces (SDF), which has links to a militant group rooted in Turkey (the Kurdistan Workers' Party, or Kurdish acronym PKK, a U.S. designated foreign terrorist organization, or FTO), against the Islamic State organization (IS/ISIS).³ In May 2025, a PKK congress decided to disband the PKK and end its armed struggle against the Turkish government, subject to various implementation steps.⁴

These U.S.-Turkey rifts appear to have somewhat diminished given U.S. and Turkish efforts to (1) strengthen NATO and Ukraine since Russia's 2022 invasion of Ukraine, and (2) work with a new, generally pro-Turkish, Sunni Arab-led transitional government in Syria after the 2024 fall of Bashar Al Asad.

Developments in Syria, which are fluid, have relevance for U.S.-Turkey relations. The May 2025 decision by a PKK congress to disband the PKK and end its more than four decades of armed struggle against the Turkish government may have the potential to resolve at least some political disagreements between Turkey and the U.S.-backed SDF without additional conflict. From 2016 to 2024, Turkey worked with other Syrian non-state forces to seize a number of areas from the SDF along or near the Turkey-Syria border. Within a context of Turkish and Syrian government opposition to Kurdish military autonomy, the SDF agreed in March 2025 to integrate into Syria's national military. However, SDF leaders (with reported support from PKK or PKK-linked figures) appear to support some measure of decentralization, amid violence this year among pro-government Sunni Arab Islamist groups and other Syrian minorities. Turkey-Israel tensions also have increased as the two countries vie for influence in Syria—further challenging relations that were already worsened by Turkey-Israel differences over (1) Turkey's continuing support for the Palestinian Sunni Islamist group Hamas (another FTO) after its October 2023 attacks and taking of hostages in Israel, (2) Israel's conduct of the war in Gaza, and (3) an official Turkish suspension of exports to Israel.

Beyond the Middle East, U.S.-Turkey differences may persist on some issues, such as Turkey's continued economic and energy cooperation with Russia, and long-standing tensions with Greece and the Republic of Cyprus. Washington and Ankara may align on other matters, such as assisting with an Azerbaijan-Armenia peace process that could lead toward normalization of Turkey-Armenia relations.

Additionally, domestic issues in Turkey could affect the trajectory of U.S.-Turkey relations. After the steady consolidation of power by President Recep Tayyip Erdogan and his Islamist-leaning Justice and Development Party (Turkish acronym AKP) over 22 years of ruling Turkey, in 2025 his government has taken arguably its strongest actions to date against Turkey's main opposition Republican People's Party (CHP). Those moves included the imprisonment of Istanbul mayor Ekrem Imamoglu, perhaps the most serious rival Erdogan has faced in national leadership polls. Turkey also faces some economic challenges; while official inflation in Turkey has dropped considerably in the last two years, it remains far higher (over 30%) than in any other Organisation for Economic Co-operation and Development (OECD) country.⁵

To date, the second Trump Administration has outwardly welcomed closer relations with Turkey, with some reported softening by each side toward the other on certain foreign policy matters, and U.S. officials possibly downplaying the controversial Turkish domestic issues mentioned above.⁶ President Donald Trump has congratulated President Erdogan on Turkey's increased influence in Syria while surmising that the Trump Administration could solve any problem with Turkey "as long as you're reasonable."⁷ U.S. Ambassador to Turkey and Special Envoy for Syria Thomas Barrack has indicated that Turkey has a key role in the Middle East, saying, "Türkiye has never gotten the elevation of the relevance that it should have as such a major regional player."⁸ However, according to one source, "There is still no consensus in the State Department and at US Central Command on how to deal with Turkey, analysts say, and even less sympathy there for Mr Erdogan."⁹

Members of Congress may consider legislative and oversight options regarding Turkey, including on possible arms sales and how to address existing sanctions and legislative conditions. Congressional actions in response to Turkish policies that diverge from U.S. stances have influenced U.S.-Turkey relations. For example, in response to Turkey's 2019 S-400 acquisition from Russia, Congress placed conditions on some arms sales, and some Members urged the first Trump Administration to impose related congressionally authorized sanctions on Turkey, which it did in 2020.¹⁰ However, amid heightened efforts to strengthen NATO and Ukraine since 2022, Congress has not blocked the advancement of possible U.S. sales of upgraded F-16 fighter aircraft or advanced munitions to Turkey, though some Members support restrictions or limitations on those proposed sales or other potential U.S.-Turkey defense transactions. A motion failed in the Senate in February 2024 (by a 13-79 vote) to discharge a proposed joint resolution of disapproval (S.J.Res. 60 from the 118^th Congress) regarding the possible F-16 sale from the Senate Foreign Relations Committee.¹¹

For additional background, see CRS Report R41368, Turkey (Türkiye): Background and U.S. Relations, by Jim Zanotti and Clayton Thomas. See Figure 1 for a map and basic facts about Turkey.

Figure 1. Turkey at a Glance
Geography	Area: 783,562 sq km (302,535 sq. mile), slightly larger than Texas
People	Population: 84,119,531 (2024). Most populous cities: Istanbul 15.8 mil, Ankara 5.4 mil, Izmir 3.1 mil, Bursa 2.1 mil, Adana 1.8 mil, Gaziantep 1.8 mil. (2023) % of population 14 or younger: 21.7% (2024) Ethnic groups: Turks 70%-75%; Kurds 19%; Other minorities 6%-11% (2016) Religion: Muslim 99.8% (mostly Sunni), Others (mainly Christian and Jewish) 0.2% Literacy: 97% (male 99%, female 95%) (2021)
Economy	GDP per capita (at purchasing power parity): $47,350 Real GDP growth: 2.7% Inflation: 33.0% (as of August 2025) Unemployment: 9.4% Budget deficit as % of GDP: 3.8% Public debt as % of GDP: 26.7% Current account deficit as % of GDP: 1.2%

Sources: Graphic created by CRS. Map boundaries and information generated by Hannah Fischer using State Department Boundaries (2011); Esri (2014); ArcWorld (2014); DeLorme (2014). Fact information (2025 projections unless otherwise specified) from International Monetary Fund (IMF); IMF World Economic Outlook Database; Economist Intelligence Unit; Central Intelligence Agency, The World Factbook; and the Turkish Statistical Institute.

Outlook

Turkey's apparent interest in acting more independently, along with leverage that may come from its status as a regional power, could lead Turkey and the United States to adopt or accept more of a case-by-case approach to bilateral cooperation than in earlier eras. Turkey and other "global swing states" such as Saudi Arabia and India appear to increasingly seek advantages in a global system with intensifying great-power competition, including a tendency to hedge between the West and other countries that project global influence.¹² While Turkey's NATO membership is important for its security and the European Union (EU) is Turkey's largest trading partner and foreign investor (accounting for 70% of foreign direct investment in Turkey),¹³ Turkey reportedly seeks to join the BRICS (Brazil, Russia, India, the People's Republic of China [PRC], South Africa) group and the PRC- and Russia-led Shanghai Cooperation Organization (SCO) as well.¹⁴ President Erdogan has said, "Turkey can become a strong, prosperous, prestigious and effective country if it improves its relations with the East and the West simultaneously."¹⁵

As major developments evolve with implications for bilateral relations, Turkey reportedly seeks the following from the United States:

• Purchases of advanced fighter aircraft—F-16s and possibly fifth-generation F-35s—and the removal of defense-related U.S. sanctions imposed in 2020 under the Countering America's Adversaries Through Sanctions Act (CAATSA, P.L. 115-44). U.S. legislation currently prohibits the transfer of F-35s (or certain related items) to Turkey unless Turkey no longer possesses the Russian-origin S-400 system (or other associated items).
• Support for a transition in Syria from Kurdish-led SDF forces controlling key areas of northeast Syria and countering the Islamic State, to an arrangement in which Sunni Arab-led Syrian government forces take over these functions with backing from Turkey and other neighboring states (Jordan, Iraq, and perhaps Lebanon).
• Acceptance and encouragement of a larger Turkish role in surrounding regions, including the Middle East, eastern Mediterranean, Black Sea, and the South Caucasus.

Analysts debate whether potential strategic and economic advantages from U.S. partnership with Turkey, including potential cooperation on defense technology and rare earth minerals, should incline the Trump Administration and Congress toward greater engagement, or whether Turkey's policies on regional issues, or controversies with civil liberties and rule of law should give U.S. policymakers and lawmakers pause about closer cooperation.¹⁶ U.S. policy on Turkey could be shaped by the following considerations:

• Potential benefits and drawbacks of closer partnership. What are potential benefits from maintaining and/or strengthening relations with Turkey given its geopolitical centrality to key areas of conflict and strategic land and maritime corridors; its demonstrated ability and potential to affect military, political, and economic developments in several surrounding regions; and the potentially greater options regional powers like Turkey may have in an era of intensifying great-power competition? What are potential drawbacks to easing restrictions on and deepening partnership with Turkey when Turkey may still: contend with Syrian Kurds that have partnered with U.S. forces; be unwilling to give up certain aspects of its cooperation with Russia; support and perhaps host Hamas while taking political and economic action against Israel; and maintain longtime disagreements with Greece and the Republic of Cyprus on various political-military, geographic, and energy issues?
• Impact of Turkish leadership on key issues. To what extent do Turkish policies that differ from U.S. preferences reflect Turkish national consensus, and to what extent might they be more specific to President Erdogan and the AKP (such as on support for Hamas or the level of cooperation with Russia)? What U.S. approaches to Turkey might cultivate more or less productive bilateral ties, either with Erdogan or other potential leaders?
• Turkey-Israel regional dynamics. In Syria and the broader region, can Turkey and Israel minimize their disagreements and pursue common interests (like reducing Iran's influence), or do tensions that have arisen in 2025 foreshadow greater contention between Turkey and Israel over their respective roles in the regional order?
• Risks of Turkish alignment with U.S. rivals. What, if anything, could lead to greater Turkish alignment with U.S. rivals like Russia or the PRC? U.S. unwillingness to share advanced defense technology with Turkey, or disagreements with Turkey on key foreign policy issues? Russian or PRC initiatives to bolster Turkish military or economic strength? Domestic Turkish developments toward authoritarianism or instability? If Turkey became more adversarial to U.S. interests, what would be the regional and global consequences?

The 119^th Congress may face some decision points on Turkey, among them possible F-35 sales. Ambassador Barrack predicted in June 2025 that by the end of the year, U.S. and Turkish officials will resolve their impasse on a possible sale of F-35s, and "Congress will support an intelligent conclusion."¹⁷ In a July 2025 Senate Foreign Relations Committee hearing, Chairman Jim Risch said that he had previously placed a "hold" on the F-35s and would "continue to have that hold for a lot of different reasons."¹⁸ Additionally, Congress may take further action on legislative proposals with relevance for U.S.-Turkey relations, including some from the 119^th Congress or that may resurface in some form from bills or resolutions introduced previously.¹⁹

Domestic Issues

Political Developments Under Erdogan's Rule

President Erdogan (who became prime minister in 2003, was elected president in 2014, and then reelected twice) has probably been the most consequential political figure for the Turkish republic since its founder Mustafa Kemal Ataturk. As he and the AKP have steadily deepened their control over the country's populace and institutions, U.S. and EU officials have expressed a number of concerns about authoritarian governance and erosion of rule of law and civil liberties in Turkey.²⁰ Many observers describe Erdogan as a polarizing figure, and elections have reflected roughly equal portions of the country supporting and opposing his rule.

The AKP was dealt a setback in March 2024 local elections. The main opposition and secular-leaning CHP retained control over key mayoralties it won in 2019, won additional mayoralties, and captured a larger share of the nationwide vote, reportedly with considerable support from Kurdish political actors and voters.

In 2025, Erdogan and his nationalist coalition partners may be seeking to draw Kurdish support from the CHP in hopes of obtaining a parliamentary supermajority. Doing so could allow Erdogan to seek another presidential term in May 2028 or earlier, and possibly amend the constitution. During his first years in office, Erdogan had courted Kurdish support, until a previous initiative at Kurdish reconciliation broke down with the end of a Turkey-PKK ceasefire in 2015. Since the PKK began its on-and-off insurgency against Turkish authorities in the early 1980s, the Turkish military's approach to neutralizing the PKK has routinely been criticized by Western governments and human rights organizations for being overly punitive towards ethnic Kurds, who constitute about 19% of Turkey's population (see Figure 1). Turkish authorities have imprisoned thousands and displaced or disrupted the livelihoods of hundreds of thousands of others for suspected PKK involvement or sympathies.²⁴

Since late 2024, the government has engaged with imprisoned PKK leader Abdullah Ocalan in talks to get the PKK to renounce violence, possibly in exchange for the formalization of certain Kurdish rights in Turkey. In February 2025, Ocalan called for the PKK to disarm and dissolve. In response, the PKK declared a ceasefire and has publicly appealed for Ocalan's release from prison so he can oversee any potential dissolution.²⁵ In May, a PKK congress decided to disband the organization and end armed struggle against the Turkish government, and Turkish officials welcomed the news while awaiting "practical steps" such as the potential disarmament and demobilization of PKK fighters in Turkey, Iraq, Syria, and elsewhere.²⁶ Turkey's parliament formed a committee in August "charged with proposing and supervising legal and political reforms aimed at advancing the peace process."²⁷

In parallel with the Turkey-PKK rapprochement, government authorities have taken a number of actions against leaders from both the main opposition CHP and pro-Kurdish circles.²⁸ In the apparent crackdown against the CHP, as of September 2025, 16 mayors and more than 500 people have reportedly been arrested.²⁹ These and other government measures have prompted some opposition supporters and observers to speculate that Erdogan might be seeking to further divide, demoralize, or disqualify the opposition.³⁰ For example, CHP figures assert that cases targeting party chairman Ozgur Ozel are politically motivated. A court could determine by late October whether to nullify Ozel's chairmanship on the basis of alleged irregularities in the 2023 party congress that elected him.³¹ In apparent hopes of countering or preempting a possible annulment of the 2023 party congress, the CHP is reportedly seeking to hold new leadership elections in late September.³² A September court decision to replace the CHP's Istanbul leader has exacerbated domestic tensions.³³

In March 2025, Istanbul's CHP mayor and Erdogan's likeliest presidential rival Ekrem Imamoglu was imprisoned on various corruption-related charges, removing him from office at least temporarily and exacerbating political and economic uncertainty.³⁴ Imamoglu's arrest came days before a CHP primary officially selecting Imamoglu as the party's next presidential candidate. Imamoglu and other CHP leaders denounced his arrest as politically motivated and encouraged nonviolent protests that attracted hundreds of thousands of people. In response, Erdogan's government insisted that Imamoglu's detention came from an independent investigation, and arrested more than 2,000 protesters while blaming the CHP for fomenting instability. Erdogan may see parallels between Imamoglu's rise and his own, having leveraged his status as Istanbul's mayor during the 1990s to become the country's most popular political figure. One Turkish journalist wrote that the timing of Imamoglu's arrest may have stemmed from a relative lack of U.S. concern about Turkish domestic developments, a possible unwillingness by pro-Kurdish leaders to confront the government amid efforts toward Turkey-PKK rapprochement, and a calculation by Erdogan that he has time to recover from any effect the arrest and its fallout may have on his popularity.³⁵ Following Imamoglu's arrest, Secretary of State Marco Rubio said that the Administration does not like to see "these things happening inside countries that we hope to partner with on a bunch of things," and that U.S. concerns are balanced with an interest in working with Turkey on various issues.³⁶

Economic Issues

For more than a decade, Turkey's currency (the lira) has been trending downward relative to the dollar, with its decline probably driven in part by broader concerns by foreign investors about Turkey's policymaking and economy.³⁷ It has lost more than 91% of its value against the dollar since 2018, with much of the decrease coming after major interest rate cuts that President Erdogan backed from 2021 to 2023. Official annual inflation reached a 24-year peak of 86% in October 2022.³⁸ While inflation has dropped considerably in the last two years, it remains over 30%.

The currency and inflation crisis in Turkey has dramatically affected consumers' cost of living and the cost of international borrowing (mostly conducted in U.S. dollars) for banks and private sector companies. Turkey's manufacturing-based economy has remained relatively resilient and is anchored by its customs union with the EU.

Turkey's large population, relative lack of domestic hydrocarbon resources, and Eurasian geography make it an important global energy consumer and transit country.³⁹ The Turkish government seeks to diversify both the mix of its energy sources and its import partners. Turkey receives much of its oil and natural gas via pipelines from Russia and other countries, with some of it transiting Turkey to other destinations, including Europe. A Russian-owned company is assisting Turkey with its first nuclear power plant—currently scheduled to go online in 2026—on the Mediterranean coast at Akkuyu. During the 2020s, Turkey has increased liquefied natural gas imports from the United States and other countries, and broader U.S.-Turkey cooperation may be possible on a variety of energy initiatives. Turkish disputes with neighboring countries over offshore energy rights and eastern Mediterranean energy transit routes remain. Meanwhile, Turkey began production in 2023 from the offshore Sakarya natural gas field in the Black Sea.

Selected Foreign Policy and Defense Issues

Regular parts of Turkey's foreign policy and defense agenda include

• continued expansion of Turkey's arms industry and arms exports, including a renowned drone program and plans for integrated air defense;⁴⁶
• attempts to broaden Turkish influence and strengthen ties with countries in surrounding regions (such as Eastern Europe and the Balkans, the Middle East, Africa, the Caucasus, and Central Asia);⁴⁷ and
• a mix of military, economic, and diplomatic means to maximize Turkish self-reliance, deter neighboring countries or groups that may present current or potential threats, and prevent active conflicts or political disputes near Turkey (such as in Ukraine, Syria, Iraq, Libya, Armenia and Azerbaijan, and Cyprus) from undermining Turkish national security or domestic stability (see Figure 2).⁴⁸

Figure 2. Turkey's Military Presence: Selected Sites

Source: Bloomberg, March 2024, with minor modifications by CRS.

U.S./NATO Strategic Relationship and Military Presence

Turkey's proximity to conflict in the Middle East and Eurasia has made the continuing availability of its territory for the stationing and transport of arms, cargo, and personnel valuable for the United States and NATO. In addition to Incirlik Air Base near the southern Turkish city of Adana, other key U.S./NATO sites include an early warning missile defense radar in eastern Turkey and a NATO ground forces command in Izmir (see Figure 3). Turkey also controls access to and from the Black Sea through the Bosphorus (alt. Bosporus) and Dardanelles Straits (the Straits).

Figure 3. Map of U.S. and NATO Military Presence in Turkey

Sources: Created by CRS using data gathered from the Department of Defense, NATO, and various media outlets since 2011. Note: All locations are approximate.

For Turkey, NATO's traditional importance has been to mitigate Turkish concerns about encroachment by neighbors, such as the Soviet Union's aggressive post-World War II posturing leading up to the Cold War. Additionally, NATO security guarantees compensate Turkey for a general lack of nationally owned strategic defense and deterrence capabilities.⁴⁹ In more recent arenas of conflict like Ukraine and Syria, Turkey's possible interest in countering Russian objectives may be partly motivating Turkey's military operations and arms exports.⁵⁰ In April 2024, Turkey suspended its obligations under the Treaty on Conventional Armed Forces in Europe, joining other NATO allies who had previously taken this step after Russia withdrew from the agreement in 2023.⁵¹ In June 2025, an unnamed Turkish defense ministry source was cited as saying that Turkey supports NATO's decision to "more than double its defense spending benchmark to 5% of GDP by 2035 and is already exceeding the previous 2% benchmark."⁵²

Some of Turkey's actions in the 2020s have arguably undermined NATO unity. While seeking to persuade or compel other alliance members to distance themselves from PKK-linked Syrian Kurds that Turkey views as adversaries, Turkey delayed the following NATO initiatives before ultimately agreeing to them:

Finland's and Sweden's NATO membership applications, which came shortly after Russia's 2022 invasion of Ukraine.

A NATO defense plan proposed in 2020 for Poland and the Baltic states.

Tensions between Turkey and other NATO members during the 2020s have fueled internal U.S./NATO discussions about the continued use of Turkish bases. Some reports suggest that expanded or potentially expanded U.S. military presences in places such as Greece, Cyprus, and Jordan might be connected with concerns about Turkey.⁵³

U.S.-Turkey Defense Cooperation (F-16s, F-35s, and Sanctions)

In June 2024, five months after the Biden Administration's formal notification to Congress of a proposed F-16 fighter aircraft sale to Turkey, the State Department announced that Turkey had signed a letter of offer and acceptance. The original deal was estimated at $23 billion for the purchase of 40 new F-16s, 79 modernization kits for existing F-16s, and related munitions and equipment.⁵⁴

In November 2024, Turkish Defense Minister Yasar Guler stated in a Turkish parliamentary hearing that Turkey would no longer purchase the 79 F-16 modernization kits because he said Turkish Aerospace Industries is capable of making similar upgrades domestically. Under those terms, a modified deal would likely be worth $7 billion.⁵⁵ Reportedly, Turkey may seek U.S. agreement to give Turkey access to F-16 source codes and embedded software controlling the aircraft's systems (also known as the Operational Flight Program), possibly enabling greater integration of Turkish domestically produced weapons and systems into the F-16s.⁵⁶

Alternatively, if U.S. and Turkish officials reach an arrangement to allow Turkey to acquire F-35 fifth-generation fighter aircraft, Turkey may seek to scrap the F-16 deal altogether. Turkish acquisition of F-35s could decrease any relative military advantages other countries might have, including Israel (which already operates F-35s) and Greece (which expects to acquire them).⁵⁷

Turkey was an original member of the U.S.-led consortium formed to contribute to the development and manufacture of the F-35, but was removed in July 2019 due to its procurement of the Russian S-400 surface-to-air defense system.⁵⁸ In announcing the removal, Defense Department⁵⁹ officials cited concerns about possible Russian use of the S-400 to collect intelligence on F-35 stealth capabilities.⁶⁰ Turkey's S-400 acquisition also led the first Trump Administration to impose some sanctions in December 2020 on a Turkish defense procurement agency and associated officials for their role in the transaction, under the Countering America's Adversaries Through Sanctions Act (CAATSA); those sanctions designations remain in place.

Congress enacted a provision (Section 1245) in the FY2020 National Defense Authorization Act (NDAA, P.L. 116-92) prohibiting the Defense Department from transferring F-35s to Turkey unless Turkey no longer possesses the S-400 (or other associated items). Six Turkish-owned F-35s remain in storage in the United States, and the $1.7 billion paid for the F-35s apparently is still in U.S. hands.⁶¹ In the FY2021 NDAA (P.L. 116-283), Congress enacted another provision (Section 1241) relating to the S-400 transaction and the possible imposition and termination of CAATSA sanctions.

Some reports since 2024 indicate that U.S. and Turkish officials have been discussing options regarding the S-400's status that might lead to U.S. approval of an F-35 sale.⁶² In a March 2025 phone call between President Erdogan and President Donald Trump, President Trump (according to two unnamed sources) reportedly expressed openness to an F-35 sale if the two countries can agree to an arrangement by which the S-400 is rendered inoperable. Two possible options could be a partial dismantling of the system or moving it to a U.S.-controlled base in Turkey.⁶³ Other reports have stated that U.S. and Turkish officials have agreed to begin technical talks for the removal of sanctions. Turkish Foreign Minister Hakan Fidan stated in April that CAATSA sanctions have to date obstructed the procurement of around $20 billion in spare parts for F-16s by entities involved with Turkey's defense industry.⁶⁴ It is unclear how the FY2020 and FY2021 NDAA provisions mentioned above might apply to U.S. actions in response to potential changes to the status of Turkey's S-400 system. In response to an August 2025 letter from 40 Members of Congress, the State Department stated that the Administration is committed to complying with U.S. law, including CAATSA, and that the U.S. position "on Turkey's acquisition and continued possession of the Russian S-400 system has not changed."⁶⁵

Some House Members proposed amendments to the House Armed Services Committee-reported FY2026 NDAA (H.R. 3838) that would have placed additional conditions or restrictions on U.S. defense transactions with Turkey, stemming from apparent concerns by some lawmakers regarding Turkish policies with respect to Russia, Greece, Cyprus, Israel, Hamas, Syria, Iran, and/or China.⁶⁶ The House passed H.R. 3838 in September 2025 without including any of these proposed amendments.

Amid speculation regarding potential U.S.-Turkey fighter aircraft transactions, in May 2025, the Trump Administration formally notified Congress of an estimated $304 million possible sale to Turkey of air-to-air missiles.⁶⁷

Additionally, Turkish officials have reportedly expressed interest in acquiring 40 Eurofighter Typhoon fighter aircraft.⁶⁸ If Turkey does procure these jets, it would follow a practice that several other U.S. partners in the region—including Greece and a number of Arab states—have established in diversifying their Western suppliers of combat aircraft.⁶⁹

Turkey also is moving forward with efforts to build the TF Kaan, a domestically produced fighter with some stealth capabilities, but mass production would reportedly—according to some estimates—begin at earliest in the late-2020s, and perhaps several years later.⁷⁰ Prototypes of the TF Kaan use U.S.-origin General Electric F110 engines, and initial production versions of the aircraft would depend on acquiring more of these engines while Turkey reportedly seeks to overcome challenges in developing a domestic engine for later versions.⁷¹

Syria and Regional Implications (Kurds, U.S. Forces, Israel, and Iran)

Turkey may be the most influential outside actor in Syria following the December 2024 collapse of Bashar al Asad's (alt. Assad) regime, and with the diminished influence of Asad's main foreign protectors Russia and Iran. Ankara has provided various forms of support to Syria's interim authorities—led mainly by figures from Hay'at Tahrir al Sham (HTS, an Al Qaeda-rooted organization that was an FTO until the Trump Administration lifted this designation in July 2025, and remains a Specially Designated Global Terrorist entity)—in apparent hopes of exercising leverage and securing close political, military, and commercial ties.⁷² President Trump's elimination or waiver of many U.S. sanctions on Syria via actions in May 2025 and a June executive order (EO 14312) may facilitate Turkish economic and other engagement that could bolster Turkey's influence in Syria and the broader region. Nevertheless, the United States retains the option to impose sanctions on entities for actions in Syria.

Turkish officials also have sought to weaken the U.S.-backed, Kurdish-led SDF, largely owing to its links to the PKK, which waged a decades-long insurgency in Turkey before announcing its intention to disband in May 2025. Since 2016, Turkey and its allied militias known as the Syrian National Army (SNA, which began to integrate with Syrian government forces in 2025) captured much of the northern Syria border area from the SDF, including some strategically located towns after Asad's ouster in December 2024 (see Figure 4). Additionally, Turkey is encouraging the voluntary return of some of the two to three million Syrian refugees in Turkey; the Turkish interior ministry reported in August 2025 that more than 400,000 refugees have returned since the end of Asad's rule.⁷³ These developments could affect Syria's domestic cohesion and have repercussions for the presence of several hundred U.S. troops currently supporting the SDF's counter-IS efforts.

Figure 4. Syria: Areas of Influence and Operation (as of July 29, 2025)

Source: CRS using CJTF-OIR reporting to Lead Inspector General, media and social media reporting, and ESRI and U.S. State Department data. All areas of influence approximate and subject to change.

U.S. forces and counter-IS mission. Trump Administration decisions regarding U.S. troop deployments in Syria are factors affecting future developments. In April 2025, the Pentagon chief spokesperson announced a consolidation of U.S. forces in Syria, in which a "deliberate and conditions-based process" could bring the direct U.S. presence down from about 2,000 to less than 1,000. The spokesperson reiterated U.S. support for counter-IS efforts in Syria, and a media report citing two unnamed senior U.S. officials said that U.S. personnel would continue to assist the Kurdish-led SDF and help operate IS-related detention camps.⁷⁴ According to the U.S.-led Combined Joint Task Force - Operation Inherent Resolve, as of mid-2025, "Coalition forces are not providing any support to the SDF against the Turkish military or the Turkish-backed fighters."⁷⁵ The withdrawal of U.S. forces from Syria or the lack of U.S. assurances of force protection to partner forces could affect the various parties' actions, with possible implications for Syrian domestic and regional stability, counterterrorism concerns, and humanitarian needs. Some U.S. troops have reportedly pulled back from areas with Arab-majority populations, apparently limiting the SDF's effective control over these regions.⁷⁶

Turkey has sought to partner with Syria's interim government, as well as Jordan, Iraq, and Lebanon, to establish a multilateral counter-IS mechanism that could eventually replace the SDF.⁷⁷ When President Trump met Syria's interim president Ahmed Al Sharaa in May 2025 in Saudi Arabia, the White House press secretary said that President Trump urged Sharaa to (among other things) "Assume responsibility for ISIS detention centers in Northeast Syria."⁷⁸

Kurdish-led SDF: potential next steps. In March 2025, Syria's interim authorities and the Kurdish-led SDF announced a deal in which the parties agreed to integrate "all civil and military institutions in northeastern Syria into the administration of the Syrian state, including border crossings, the [Qamishli International] airport, and oil and gas fields," while guaranteeing citizenship and constitutional rights to the Kurdish community in Syria.⁷⁹ Turkish leaders have expressed hopes that the deal between Syrian interim authorities and the SDF will end SDF efforts to obtain Kurdish political and military autonomy in Syria, and will lead the SDF to expel any PKK fighters from Syria. Turkey and the SNA reportedly halted attacks on the SDF a few weeks after the March deal between the SDF and Damascus.⁸⁰ Since then, some clashes have reportedly occurred in northern Syria between the SDF and factions aligned with the Syrian government.⁸¹

While a broad array of Syrian Kurdish political groups (including those affiliated with non-PKK Iraqi Kurds) have expressed support for some decentralization within Syria, Syria's interim authorities, with Turkey's support, have rejected the prospect of formal decentralization or federal autonomy. Possible resolution of Turkey's tensions with the SDF could be linked to potential rapprochement between Turkey and the PKK, though Kurdish SDF leaders insist that their group is separate from the PKK.⁸² Initial dialogue led to an SDF handover of security control to Syrian national authorities in some Kurdish-populated areas in or near Aleppo.⁸³ The SDF has insisted on preserving its "distinct identity" within Syria's military, amid ongoing challenges in addressing mutual concerns expressed by Kurds and Sunni Arabs in areas of northeast Syria about possible mistreatment if the other ethnic group controls governance there.⁸⁴

In light of violence among pro-government Sunni Arab Islamist groups and other Syrian minorities (Druze, Alawites, and Christians), the SDF has expressed concern that ceding its autonomy would leave Syrian Kurds vulnerable to attack.⁸⁵ In July 2025, Turkish Foreign Minister Hakan Fidan called on the SDF to integrate with Syria's central government and for the leading Kurdish force in the SDF—the People's Defense Units (Kurdish acronym YPG)—to "lay down its arms."⁸⁶ PKK leader Abdullah Ocalan has reportedly agreed with "top PKK operatives" that the YPG should only disarm "when an acceptable agreement is struck with the central government."⁸⁷ In August 2025, a media source cited sources indicating that SDF delays in integrating with Syria's national authorities would not likely lead to direct Turkish intervention against the SDF, but Turkey might indirectly support "a limited operation by the Syrian army."⁸⁸

Regional implications (including Iran and Israel). Turkey's role in Syria and related developments could lead to closer Turkish cooperation with the United States, Israel, and Arab states against Iran, or could intensify tensions with these actors regarding Syria's future and its implications for the region. Turkey may seek to take advantage of recent Iranian setbacks in the region, and perhaps leverage potential rapprochement with the PKK, to increase its sway in Syria, Iraq, and elsewhere.⁸⁹

Israeli actions since Asad's ouster targeting Syrian bases and other strategic sites, advancing its military into parts of southern Syria, and seeking to protect Syrian minorities, may be partly aimed at countering Turkish influence and preventing the possible Turkish deployment of military assets in central Syria.⁹⁰ Reportedly, Israeli and Turkish officials have held talks aimed at preventing an Israel-Turkey military clash and otherwise coordinating on Syria. According to one source as of June 2025, "A hotline now reportedly connects the two countries' militaries to prevent direct confrontation between the two inside Syria. However, getting the two sides to agree on each other's red lines will likely prove far more difficult."⁹¹ Turkish officials apparently have sought to convince Israel that the two countries' interests align in preventing Iran from regaining influence in post-Asad Syria.⁹²

In August 2025, Turkey and Syria signed a "joint training consultancy memorandum of understanding [MOU]" as an apparent step toward a substantive military cooperation deal.⁹³ Turkish officials reportedly anticipate strengthening Syria's regular army with arms and other forms of support, with the apparent goal of helping the Syrian army establish long-term stability.⁹⁴ While Turkish and Syrian officials apparently are discussing the potential deployment of Turkish troops to some Syrian bases, the MOU supposedly does not address it.⁹⁵ According to one media report, Turkey may seek to avoid providing any weapons that could provoke Israel given existing tensions.⁹⁶ Nevertheless, in September, an unnamed Israeli "security source" was cited as saying that an Israeli strike in Syria targeted depots purportedly holding Turkish-made missiles and air defense equipment.⁹⁷ Later in September, Turkish Foreign Minister Fidan stated that Israel is pursuing "regional expansionism" aimed at leaving Israel's neighboring states divided.⁹⁸

Israel and the Palestinians (Including Hamas)

Since the October 2023 Hamas-led attacks and hostage-taking in Israel, and ensuing war, Turkey-Israel ties have come under strain. Turkey and Erdogan had been improving relations with Israel prior to October 2023, and Turkey had said that the countries were contemplating closer energy cooperation.⁹⁹ Tension between Turkey and Israel on Palestinian issues flared up previously on a number of previous occasions, including in 2010 when Israeli commandos killed ten Turkish citizens in clashes aboard the Mavi Marmara, part of a private Turkish flotilla seeking to provide relief supplies to the Gaza Strip despite Israeli maritime restrictions. The ongoing Israel-Hamas war and humanitarian crisis in Gaza have sharpened tensions. Despite maintaining diplomatic relations to date, Turkey and Israel may face challenges in restoring bilateral ties to their pre-October 2023 status.¹⁰⁰ Israel withdrew its diplomats from Turkey in October 2023, and Turkey withdrew its ambassador from Israel in November 2023.¹⁰¹ In August 2025, Israeli Prime Minister Benjamin Netanyahu labeled World War I-era Ottoman Empire actions toward Armenians as "genocide";¹⁰² Turkey's foreign ministry condemned and rejected Netanyahu's remarks.¹⁰³

Since the outbreak of Israel-Hamas conflict, President Erdogan has strongly criticized Israel for its actions in Gaza,¹⁰⁴ and the United States for supporting Israel. In May 2024, Turkey's trade ministry announced that Turkey had officially stopped import and export transactions with Israel in all goods until "a permanent cease-fire is established and uninterrupted humanitarian aid is allowed into Gaza."¹⁰⁵ (Israeli trade data and other open sources reportedly reveal that exports possibly continue at a reduced level via third countries.¹⁰⁶)

Adding to strains with Israel, Turkey has provided consistent political support to Hamas, and has hosted Hamas political officials from time to time. Turkey also maintains ties with Palestine Liberation Organization (PLO) Chairman and Palestinian Authority (PA) President Mahmoud Abbas, who administers partial PA self-rule in the West Bank¹⁰⁷ and heads Hamas's secular rival faction Fatah. Erdogan may be interested in helping broker future agreements between the two factions.

A Treasury Department official visited Turkey in November 2023 and raised concern about Hamas's ability to operate in Turkey to fund potential future attacks; Turkish officials reportedly responded that while they do not consider Hamas to be a terrorist group, Turkey "would not tolerate violations of domestic laws including money laundering and direct funding of violent acts."¹⁰⁸ Since October 2023, Treasury has imposed sanctions on several Turkey-based Hamas operatives or Hamas-linked companies.¹⁰⁹

Russia and Ukraine

After Russia's 2022 invasion of Ukraine, U.S. and Turkish interests may overlap to some extent in countering Russian aims—including along the Black Sea coast. Turkey has helped strengthen Ukraine's defense capabilities in parallel with other NATO countries (even assisting with U.S. arms manufacturing),¹¹⁰ closed the Bosphorus and Dardanelles Straits to belligerent warships,¹¹¹ and helped facilitate Ukrainian grain exports. Amid international efforts to facilitate a ceasefire in early 2025, Turkey became a venue for Russia-Ukraine talks (as it did previously in 2022), and Ukrainian President Volodymyr Zelensky has openly sought Turkish security guarantees for Ukraine (alongside similar efforts to procure U.S. and EU guarantees).¹¹²

Turkey retains close energy and economic ties with Russia, which is the top oil and natural gas supplier to Turkey. Russia reportedly provided about 65% of Turkey's oil imports and more than 45% of its gas imports in 2024. To avoid being targeted by U.S. sanctions against Russia's Gazprombank, Turkey reportedly arranged to route its payments for gas imports via the Russian subsidiary of an Austrian bank, with an unnamed senior Turkish official cited in May 2025 as saying that "Washington was comfortable with this solution."¹²⁰ In August 2025, the Trump Administration imposed a 25% secondary tariff on India for importing oil from Russia; if the Administration imposed a similar tariff on Turkey, Turkey could "find itself in a difficult balancing act between energy security and trade interests."¹²¹

Turkey has not joined Western economic sanctions against Russia. Turkish leaders have said they do not consider Turkey bound by other countries' sanctions against Russia, but would prevent the use of Turkish jurisdiction to evade sanctions. In February 2025, the Wall Street Journal reported that Justice Department investigators found that Russian transfers of more than $5 billion to banks in Turkey in 2022—ostensibly for Turkey's first nuclear power plant, which Russia's state-owned Rosatom is building—were used "to dance around U.S. sanctions imposed on Russia's central bank."¹²² Reportedly largely in response to U.S. actions (including sanctions designations on some Turkey-based entities and individuals¹²³), Turkey has greatly decreased its trade with Russia in items with potential defense applications, according to some open sources.¹²⁴

Other Regional Relationships

Since 2022, Turkey has improved relations with many surrounding countries that had clashed with Turkey politically over the previous decade on issues including the role of Islamist movements, maritime boundaries and energy cooperation, and the Israeli-Palestinian conflict. For example, Turkey has bolstered its political and economic relations with Saudi Arabia, the United Arab Emirates, and Egypt. Turkey's relations with Greece have improved somewhat after a stretch between 2020 and 2022 that featured heated disputes—and apparent Turkish threats of potential military action—over various political-military, geographic, and energy issues involving Cyprus and the Aegean and eastern Mediterranean regions. Nevertheless, the decades-long Turkey-Greece differences on these issues remain unresolved.

Moreover, prospects may be improving for Turkey-Armenia ties. Turkey (along with Israel) provided material support to Azerbaijan in its successful military campaigns in 2020 and 2023 to take control of the disputed Nagorno-Karabakh region from Armenia. Since then, Azerbaijan-Armenia peace treaty talks and a Turkey-Armenia normalization process have proceeded in parallel. In August 2025 at the White House, Azerbaijan and Armenia initialed a peace agreement (apparently subject to future signing and ratification), and signed a joint declaration regarding their meeting.¹²⁵ The joint declaration references an agreement by Armenia to cooperate with the United States "and mutually determined third parties, to set forth a framework for" a transit route (under Armenian sovereignty) that would fully connect Azerbaijan and Turkey; the declaration refers to the project as the Trump Route for International Peace and Prosperity (TRIPP). While the project could provide geopolitical and economic benefits to the United States and Turkey—including via commercial links to the energy-rich Caspian Sea basin and Central Asia—Iran has expressed concern about the project, and Russia also could potentially complicate its implementation. Additionally, various political and military obstacles remain to the signing and ratification of the Azerbaijan-Armenia peace deal, without which full Turkey-Armenia normalization may not be likely.

Footnotes