Iran and Israel: Tension Over Syria
Updated June 5, 2019
Iran and Israel: Tension Over Syria
Iranian military operations in support of the Syrian
The evolution of the U.S. military presence in Syria could
government since 2011 have exacerbated longstanding
be one factor in Israeli calculations on this issue. The U.S.
tensions between Iran and Israel. These tensions have
base at Al Tanf in southern Syria reportedly serves as “a
worsened considerably since late 2016 as Iran has helped
critical element in the effort to prevent Iran from
Syria’s government regain key territory, and in turn has
establishing a ground line of communications from Iran
sought a more permanent military presence in Syria.
through Iraq through Syria to southern Lebanon in support
Israeli officials have described the deployment of Iran-
of Lebanese Hezbollah,” according to a former U.S.
backed forces in Syria—particularly in the southwest, near
military commander. Israeli officials favor continued U.S.
Israel’s northern border—as a significant security threat
involvement in Syria, while also preparing for the
compelling Israeli action. In January 2019, Israeli Prime
possibility that the U.S. role in countering Iran there might
Minister Binyamin Netanyahu said that Israel had struck
diminish. In mid-2019, U.S. officials stated that Israel is
“under immediate threat by Iranian forces in Syria who, if
Iranian and Hezbollah targets in Syria “hundreds of times.”
In 2018, Israeli and Iranian forces repeatedly targeted one
they can be allowed to embed themselves in that country
another in and over Syrian- and Israeli-controlled areas.
with long-range systems, would be able to open a third
front on Israel, next to Lebanon and Gaza.”
While Israel had conducted numerous air strikes inside
Syria since 2012—mostly on targets linked to weapons
Iran-Israel-Syria Dynamics: Rivalry and
shipments to Lebanese Hezbollah—the 2018 strikes
Partnership
appeared for the first time to have directly targeted Iranian
infrastructure in Syria, and reportedly killed dozens of
Iran and Israel have been adversaries since Iran’s 1979
Iranian personnel. In articulating their “redlines,” Israeli
Islamic Revolution. In the early 1980s, Iran (a Shi’a
leaders indicated that Israel would act in Syria to prevent
Muslim-majority country) helped establish the Shi’a militia
Iran from establishing permanent military bases or weapons
Hezbollah in southern Lebanon, which was occupied by
factories, and opening new “terror fronts” against Israel.
Israeli military forces from 1982 to 2000. Until recently, the
They also suggested that Israel might attack Iran directly if
threat of direct conflict involving Iran-backed forces at
Israel’s nor
Iran-backed attacks target major Israeli cities.
thern border came mainly from Hezbollah,
which has used the remaining Israeli presence in disputed
Figure 1. Reported Iranian presence in Syria
border areas to justify continued conflict with Israel. Israel
and Hezbollah fought a 34-day conflict in 2006, and Iran
has helped Hezbollah rebuild its arsenal of over 100,000
missiles and rockets in contravention of U.N. Security
Council resolutions. Nevertheless, Iran and Israel have
historically sought to avoid direct combat with one another.
Israel and Syria have technically been at war since Israel’s
founding in 1948, with subsequent military conflicts in
1967 and 1973. Israeli military forces have occupied
strategically important areas of the Golan Heights since
capturing them from Syria in 1967. (In 2019, the United
States recognized the Golan Heights as part of Israel. U.N.
Security Council Resolution 497, adopted in 1981, held that
the area of the Golan Heights controlled by Israel’s military
is occupied territory belonging to Syria.) Israel has
continued to strike Syrian targets it views as security
threats, including Syrian air defenses in Lebanon in the
1980s and a nuclear reactor in eastern Syria in 2007.
Source: Telegraph (UK), May 10, 2018.
Notes: CRS cannot independently verify reports about the parties
Iran and Syria have grown closer under the rule of Syrian
that are present at or have control over specific facilities inside Syria.
President Bashar al Asad, despite the Asad regime’s
championing of secular Arab nationalism and Iran’s
In 2019, Israeli military forces reportedly have conducted
identity as an Islamic republic and majority Persian country
additional strikes in Syria, targeting Iranian or Iranian-
at odds with most of the Arab world. Iran values Syria as a
backed forces. According to these reports, some of the
key transshipment point for the supply of weapons from
Israeli strikes precede or follow aircraft incursions or
Iran to Hezbollah, as well as Asad’s support for Iran in a
weapons fire coming from Syria.
region where most governments oppose Iran. In turn, Syria
has seen a security imperative in allying with Iran and
https://crsreports.congress.gov
Iran and Israel: Tension Over Syria
Hezbollah against Israel, which Syria views as its primary
manned by Russian personnel, are on the ground, will
external threat. Asad’s heavy reliance on Iranian aid during
necessitate greater care [when carrying out future
the civil war has further cemented bilateral ties.
operations against Iran-aligned targets in Syria].”
Syrian Civil War Triggered Iran’s
Since the September 2018 incident, Israeli air strikes appear
Expansion
to have decreased somewhat. According to some sources,
Syria’s internal conflict, which began in 2011, brought an
Iran reportedly began directly transferring weapons to
influx of Iranian, Hezbollah, and other Iran-backed militia
Hezbollah in Lebanon while reducing the use of Syria as a
fighters into Syria. These forces provided manpower,
transshipment hub.
training, equipment, weapons, and funding to the Syrian
government. By 2017, Iran had been widely observed to be
Potential Issues for Congress
developing entrenched military positions that could be used
Russia. Russia’s delivery of the S-300 to Syria raises
to project power beyond Syria.
broader questions about its role in Syria. Russia has told
Israel and the Trump Administration that it would try to
Israel has accused Hezbollah of establishing a cell in
limit Iran’s presence and influence in the country, though
Syrian-held areas of the Golan Heights, with the eventual
such limitations might not fully satisfy U.S. or Israeli
goal of launching attacks into Israel. Some press reports
expectations. Russia reportedly helped arrange for the
indicate that U.S. sanctions have diminished Iran’s ability
pullback of Iranian heavy weapons 85 km from Israel’s
to subsidize Hezbollah, contributing to an apparent decrease
Golan positions, and has blocked some Iranian efforts to
in Hezbollah forces in Syria.
acquire land in and around Damascus. U.S. officials have
stated that Russia and the United States share some
In May 2019, U.S. Ambassador James Jeffrey, the Special
common interests in Syria—such as ensuring a stable Syria
Representative for Syrian Engagement and Special Envoy
that does not become a refuge for terrorism—but also have
for the Global Coalition to Defeat ISIS, testified at a
noted that Russia has “turned a blind eye” to long-range
hearing before the House Foreign Affairs Committee that
Iranian weapons systems in Syria that threaten Israel.
Iran maintains thousands of IRCG-QF advisors in Syria,
which provide leadership for over 10,000 Iranian-backed
U.S. policy vis-à-vis Iran in Syria. In February 2019
proxies from third countries. However, Jeffrey noted,
testimony before the Senate Armed Services Committee,
General Joseph Votel, Commander of U.S. Central
...what really concerns us even more is Iranian
Command, stated that while the U.S. military deployment
power projection systems; long-range missiles,
in Syria was focused on countering the Islamic State, the
drones, radar systems, air defense capabilities; that
presence of U.S. forces at the At Tanf base in eastern Syria
you do not need to fight an internal civil war against
has “...the derivative value of being along a principal line of
a lightly-armed opposition force. That’s not what
access, line of communication that Iran and her proxies
those forces are there for. They’re there to threaten
would like to exploit.” Iran and Syria signed a new defense
Syria’s neighbors, beginning with Israel.
cooperation agreement in August 2018, which reportedly
provided for the continued presence of Iranian advisors in
Jeffrey added that the United States strongly supports
Syria. Iranian officials have stated that their military
“Israel’s efforts [...] over Syria against Iranian targets.”
presence in Syria is at the invitation of the Asad
Russia’s Role
government. In May 2019, Ambassador Jeffrey stated that
the United States would “press for the withdrawal of all
Russia’s advanced air defense systems in Syria could make
Iranian forces from the entirety of Syria,” adding that one
it more difficult for Israel to operate there. Since 2015,
of the main U.S. goals for Syria is that the country not
Russia has operated an S-400 system at Russia’s
“provide a base for Iran.”
Khmeimim air base in Lattakia, a city on Syria’s
Mediterranean coast. To date, however, Russia does not
Israeli policy and U.S. support. If conflict between Iran
appear to have acted militarily to thwart Israeli air strikes
and Israel escalates, the Administration and Congress could
against Iranian or Syrian targets, and Israel and Russia
face urgent questions regarding situational or emergency
maintain communications aimed at deconflicting their
support for Israel. The United States provides various forms
operations.
of political, military, and material support to Israel,
including co-development and co-production of missile
In addition to the S-400 that it owns and operates, Russia
defense systems (including Iron Dome, David’s Sling, and
delivered an S-300 air defense system for Syria’s military
Arrow) that were developed expressly to counter the missile
to Khmeimim airbase in October 2018. The delivery
followed Syria’s downing of a Russian military surveillance
and rocket threat from Iran and its regional allies. Iron
Dome has reportedly intercepted some rockets fired at
plane in September 2018 under disputed circumstances,
Israeli targets from Syria, and Israeli-owned, U.S.-origin
shortly after an Israeli operation in the vicinity. According
Patriot systems have reportedly hit aircraft from Syria that
to an Israeli satellite imagery analysis company, three
have crossed into Israeli-controlled areas.
launchers appeared to be operational as of February 2019. It
is unclear to what extent Russia has transferred the S-300 to
Syrian military control, and how this might affect future
Carla E. Humud, Analyst in Middle Eastern Affairs
Israeli military action in Syria. An Israeli journalist wrote
Kenneth Katzman, Specialist in Middle Eastern Affairs
that “Israel has the knowledge, experience and equipment
Jim Zanotti, Specialist in Middle Eastern Affairs
to evade the S-300, but the fact that additional batteries,
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Iran and Israel: Tension Over Syria
IF10858
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