Updated October 24, 2018
Iran and Israel: Tension Over Syria
Iranian military operations in support of the Syrian
Iran-Israel-Syria Dynamics: Rivalry and
government since 2011 have exacerbated longstanding
Partnership
tensions between Iran and Israel. These tensions have
Iran and Israel have been adversaries since Iran’s 1979
worsened considerably since late 2016 as Iran has helped
Islamic Revolution. In the early 1980s, Iran (a Shi’a
Syria’s government regain key territory, and in turn has
Muslim-majority country) helped establish the Shi’a militia
sought a more permanent military presence in Syria.
Hezbollah in southern Lebanon, which was occupied by
Israeli military forces from 1982 to 2000. Until recently, the
Israeli officials have described the deployment of Iran-
threat of direct conflict involving Iran-backed forces at
backed forces in Syria—particularly in the southwest, near
Israel’s northern border came mainly from Hezbollah,
Israel’s northern border—as a significant security threat
which has used the remaining Israeli presence in disputed
compelling Israel to act. In September 2018, Israeli
border areas to justify continued conflict with Israel. Israel
Intelligence Minister Israel Katz stated, “in the last two
and Hezbollah fought a 34-day conflict in 2006, and Iran
years Israel has taken military action more than 200 times
has helped Hezbollah rebuild its arsenal of missiles and
within Syria itself.” During 2018, Israeli and Iranian forces
rockets in contravention of U.N. Security Council
have repeatedly targeted one another in and over Syrian-
resolutions. Nevertheless, Iran and Israel have historically
and Israeli-controlled areas. While Israel has conducted
sought to avoid direct conventional war with one another.
numerous air strikes inside Syria since 2012—mostly on
targets linked to weapons shipments to Lebanese
Israel and Syria have technically been at war since Israel’s
Hezbollah—the 2018 strikes appear for the first time to
founding in 1948, with subsequent military conflicts in
have directly targeted Iranian facilities and personnel in
1967 and 1973. Israeli military forces have occupied
Syria.
strategically important areas of Syria’s Golan Heights since
1967. Israel has remained willing to strike Syrian targets it
The potential for conflict between Iran and Israel—not only
views as security threats, including Syrian air defenses in
in Syria but also in Lebanon—has significant implications
Lebanon in the 1980s and a nuclear reactor in eastern Syria
for the U.S. military profile in the region, political dealings
in 2007.
with key actors, and material support for Israel’s defense.
Iran and Syria have grown closer under the rule of Syrian
Figure 1. Reported Iranian presence in Syria
President Bashar al Asad, despite the Asad regime’s
championing of secular Arab nationalism and Iran’s
identity as an Islamic republic and majority Persian country
at odds with most of the Arab world. Iran values Syria as a
key transshipment point for the supply of weapons from
Iran to Hezbollah, as well as Asad’s support for Iran in a
region where most governments oppose Iran. In turn, Syria
has seen a security imperative in allying with Iran and
Hezbollah against Israel, which Syria views as its primary
external threat. Asad’s heavy reliance on Iranian aid during
the ongoing civil war has further cemented ties between the
two states.
Syria Civil War Triggers Iran’s Expansion
Syria’s internal conflict, which began in 2011, brought an
influx of Iranian, Hezbollah, and other Iran-backed militia
fighters into Syria. These forces provided manpower,
training, equipment, weapons, and funding to the Syrian
government. By 2017, Iran had been widely observed to be
Source: Telegraph (UK), May 10, 2018.
developing entrenched military positions that could be used
Notes: CRS cannot independently verify reports about the parties
to project power beyond Syria. In articulating their
that are present at or have control over specific facilities inside Syria.
“redlines,” Israeli leaders have indicated that Israel will act
For information on how the U.S. executive branch classifies the status
in Syria to prevent Iran from establishing permanent
of the Golan Heights, see https://www.state.gov/p/nea/ci/is/.
military bases or weapons factories, and opening new
“terror fronts” against Israel. They also have suggested that
Israel might attack Iran directly if Iran-backed attacks target
major Israeli cities.
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Iran and Israel: Tension Over Syria
2018 Incidents
how this might affect future Israeli military action in Syria.
In 2018, tensions between Iran and Israel in Syria appeared
When Russia delivered S-200 systems to Syria in the 1980s,
to escalate, increasing the possibility of a wider conflict. In
Russian personnel reportedly operated the systems for years
February 2018, an Iranian drone crossed into Israel from
before Syrian personnel took over. An Israeli journalist has
Syria, where it was shot down. Israel struck the T4 (Tiyas)
written that “Israel has the knowledge, experience and
military base in central Syria, from which it assessed the
equipment to evade the S-300, but the fact that additional
drone was launched. Syrian anti-aircraft fire downed an
batteries, manned by Russian personnel, are on the ground,
Israeli F-16 participating in the operation (the plane crashed
will necessitate greater care [when carrying out future
in northern Israel after its two crew members safely
operations against Iran-aligned targets in Syria].”
ejected). Israel then struck eight Syrian and four Iranian
military targets in Syria.
Potential Issues for Congress
Russia’s role. Russia’s delivery of the S-300 raises broader
Since then Israel has periodically targeted Iranian positions
questions about its role in Syria. Russia has told Israel and
in Syria—in response to perceived Iranian breaches of its
the Trump Administration that it would try to limit Iran’s
redlines—and has reportedly killed dozens of Iranian
presence and influence in the country, though such
personnel. Israeli Defense Minister Lieberman stated that
limitations might not fully satisfy U.S. or Israeli
Israeli strikes in May 2018 (in response to rocket fire into
expectations. Russia reportedly helped arrange for the
the Golan Heights by Iranian forces in Syria) had targeted
pullback of Iranian heavy weapons 85 km from Israel’s
“nearly all” of Iran’s military infrastructure in Syria.
Golan positions, and has blocked some Iranian efforts to
acquire land in and around Damascus.
Russia Loses a Plane and Delivers an S-300 System
In September 2018, Israel struck military targets in Syria’s
U.S. policy vis-à-vis Iran in Syria. As of late 2017, U.S.
coastal province of Lattakia. A Syrian antiaircraft battery
officials reported that approximately 2,000 U.S. military
responding to the Israeli strikes mistakenly downed a
personnel were deployed in Syria in support of counter-IS
Russian military surveillance plane, killing 15 Russian
operations. At times, Iranian proxies have directly attacked
personnel. An IDF spokesperson stated that Israeli jets were
U.S. partner forces in Syria, prompting defensive U.S.
targeting “a facility of the Syrian Armed Forces from which
airstrikes. In February 2018 testimony before the House
systems to manufacture accurate and lethal weapons were
Armed Services Committee, General Joseph Votel,
about to be transferred on behalf of Iran to Hezbollah in
Commander of U.S. Central Command, stated that while
Lebanon.”
countering Iran in Syria was not a U.S. military objective,
U.S. military personnel could “indirectly” impact Iranian
The IDF spokesperson added that Israel and the Russian
objectives in the region by bolstering local border control
military maintain a deconfliction system in Syria, stating
forces. However, in September 2018, U.S. National
that the Russian plane was not in the area of operation
Security Advisor John Bolton stated, “We’re not going to
during the IDF’s Lattakia strike and blaming “extensive and
leave [Syria] as long as Iranian troops are outside Iranian
inaccurate” Syrian antiaircraft fire for the incident.
borders and that includes Iranian proxies and militias.” Iran
and Syria signed a new defense cooperation agreement in
In response to the downing of their plane, Russian defense
August, which reportedly provides for the continued
officials announced plans to provide an S-300 air defense
presence of Iranian advisors in Syria. Iranian officials have
system to Syria. Syria had reportedly entered into a contract
stated that their military presence in Syria is at the
with Russia in 2010 to acquire the S-300, but Russia had
invitation of the Asad government.
delayed implementing the deal. Since 2015, Russia has
operated (without involvement by Syrian personnel) an S-
Israeli policy and U.S. support. If conflict between Iran
400 system at Russia’s Khmeimim air base in Lattakia.
and Israel escalates, the Administration and Congress could
face urgent questions regarding situational or emergency
In October 2018, Russian officials stated that they had
support for Israel. The United States provides various forms
completed delivery of the S-300—comprising radars,
of political, military, and material support to Israel,
control vehicles, and four launchers—to Khmeimim
including co-development and co-production of missile
airbase. Russian Defense Minister Sergei Shoigu said that
defense systems (including Iron Dome, David’s Sling, and
the system would be “integrated into Russia’s existing air-
Arrow) that were developed expressly to counter the missile
defense system” sometime in October and that “Syrian
and rocket threat from Iran and its regional allies. Iron
personnel would be trained on its use within three months.”
Dome reportedly intercepted some of the rockets fired at
Reportedly, the S-300 will have a longer range than Syria’s
Israeli targets by Iranian forces in Syria in May 2018.
other air defense systems and can identify Russian aircraft.
Shoigu also stated that Russia deployed new electronic
Carla E. Humud, Analyst in Middle Eastern Affairs
warfare systems to Syria.
Kenneth Katzman, Specialist in Middle Eastern Affairs
Jim Zanotti, Specialist in Middle Eastern Affairs
To date, Russia has not used the advanced air defenses it
has deployed in Syria to challenge Israeli air superiority in
IF10858
the region. It remains unclear whether or when Moscow
will transfer the S-300 to full Syrian military control, and
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Iran and Israel: Tension Over Syria
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https://crsreports.congress.gov | IF10858 · VERSION 4 · UPDATED