However limited or narrow in scope, striking Syria will have consequences across the "Shiite Crescent" that spans Iran, Iraq, Syria, and Lebanon. The term was coined in 2004 by Jordan's King Abdullah II, who warned that Iran's support for Shiite forces in the Middle East sought to "alter the traditional balance of power between the two main Islamic sects and pose new challenges to U.S. interests and allies." Military action in Syria could embroil the United States in civil wars from the Tigris to the Levant; U.S interests could also come under direct attack. A steely-eyed view of regional dynamics and contingency planning are critical to optimizing U.S. objectives.
Iran gains strategic depth by supporting Syria. As Iran's proxy, Syria serves several Iranian goals, including rivaling Saudi power in the region. Syria is also a launch point for terror attacks against Israel. Iran provides Hezbollah with advanced surface-to-surface missiles through a transit pipeline across Syria to Lebanon. Iran also funnels arms to militant Palestinian groups via Syria. Iran helped Syria's President Bashar al-Assad establish his stockpile of chemical weapons in the 1990s. Today, it is financing Syria. Ground forces from the Iranian Revolutionary Guard, Quds Force, and Iranian intelligence services have also joined the battlefield. The defeat of Assad by Saudi-backed Sunni Arab extremists with ties to Al-Qaeda would be a big blow to Iran.
U.S. officials say bombing Syria would send a strong message to Iran, proving America's resolve and deterring its pursuit of nuclear weapons. However, it might have the opposite effect. Iran's new President Hassan Rouhani and Foreign Minister Javad Zarif have signaled a more flexible approach in nuclear negotiations. Iran historically refuses to negotiate under duress. The Supreme leader will surely limit Rouhani's options if the U.S. intervenes in Syria. Iran could suspend diplomacy and accelerate its uranium enrichment activities. In a worst case, Iran could break-out and weaponize its nuclear energy program.
The Obama administration can mitigate these risks by engaging Iran. Now is the time to start a dialogue with Tehran about collaborating on shared interests, such as limiting Sunni extremism and Al-Qaeda's penetration in Syria, as well as constraints on Iran's enrichment activities.
The risks of intervention in Syria closely resemble the challenges of Iraq in 2003. Despite the Iran-Iraq War (1980-88), during which Saddam Hussein used chemical weapons against Iranian troops, Iran and Iraq - majority Shiite countries - have forged close cultural, economic and security cooperation since Saddam's downfall in 2003. Iranian pilgrims regularly visit Shiite holy sites in Iraq. Iranian goods flood Iraq's consumer market. Iraq is officially neutral in Syria's civil war. However, Prime Minister Nouri al-Maliki facilitates military assistance to Syria by allowing over-flight of Iranian military transport planes, ignoring strong objections of the United States.
Inspired by the struggle of their Sunni Arab brothers in Syria, radical Sunni groups in Iraq are resurgent. Today's sectarian violence in Iraq is at its highest level since peaking in 2006-07. More than 1,000 people were killed in July alone. Sectarian slaughter over the Eid-al-Fitr holiday, marking the end of Ramadan, was especially intense. Maliki responded with a heavy-hand, establishing check-points and rounding up Sunni political and community leaders, many of whom have disappeared.
The violence has also spread to Kirkuk, threatening stability in Iraqi Kurdistan. Over 20,000 Syrian Kurds fled to Iraqi Kurdistan last month after the Al-Nusra Front, Syria's Al-Qaeda affiliate, issued a fatwa condoning the killing of Kurdish women and children. Massoud Barzani, President of the Kurdistan Region of Iraq, has vowed to protect Syrian Kurds from Arab extremists. If Syria fragments, Kurds in Syria - so-called Southern Kurdistan - may seek territorial union with Iraqi Kurdistan, further polarizing Kurds and Arabs in Iraq.
The United States has little leverage over Maliki after failing to negotiate a Status of Forces Agreement, which would have left a residual force of U.S. troops in Iraq. However, it can affirm support for Kurds by subsidizing Iraqi Kurdistan's humanitarian assistance to refugees from Syria. Washington should also suspend its sale of sophisticated weapons, such as F-16s, to Baghdad until Maliki closes Iraqi air space to the transfer of Iranian weapons.
Iran's most valuable client is Hezbollah, established in the 1980s as a popular resistance movement to fight Israel's occupation of southern Lebanon. Iran supports Hezbollah through Syria, which has occupied parts of Lebanon and dominated Lebanese politics for decades. As reprisal for steps by the Future Movement to evict Syrian forces, Syrian intelligence assassinated Prime Minister Rafiq Hariri in 2005.
More than 700,000 Syrian refugees have fled to Lebanon since Syria's civil war erupted 27 months ago. The influx disrupted Lebanon's delicate ethnic balance, destabilizing the Taif Accords that established a tenuous power-sharing agreement that ended Lebanon's civil war. Syria's conflict has bled across the border into Lebanon. Sunnis in Tripoli, who back the Free Syrian Army, have targeted Hezbollah and its Shiite supporters. Attacks intensified after Hassan Nasrallah, Hezbollah's leader, sent Hezbollah militias to fight alongside Assad's forces. They went house-to-house killing Sunnis in Qusair, tilting the balance of power and enabling Assad to retake the strategic border town in June. A massive bomb blast killed scores in al-Dahiya al-Janoubiya, a Shiite suburb in south Beirut, on July 9, 2013. Nasrallah, himself, promised to join the fight in Syria against Sunnis, whom he disparages as "takfiris" apostates.
Nasrallah will calibrate his support to Assad so as to avoid alienating his constituents in Lebanon. However, Hezbollah will not sit on the sidelines if the U.S. attacks Syria. It could attack Israel with conventional weapons or use WMD-tipped missiles smuggled provided by Assad. It could also attack U.S. interests in the region, or activate sleeper cells in the U.S. to carry out strikes against America's homeland. Other than dispatching ships from the 6th Fleet in the Mediterranean to help defend Israel, there is little the United States can do to counter Hezbollah's asymmetric terror tactics.
Gulf Arab Shiites
The Shiite Crescent is more than a contiguous territory. The restive Shiite majority in Bahrain would protest a U.S. strike against Syria. Bahrain is home to the U.S. Naval Forces Central Command, which patrols the Persian Gulf and waters off East Africa. Violent unrest can also be expected against other U.S. allies in the Persian Gulf with Shiite minorities, such as Saudi Arabia and Kuwait.
Bombing Syria won't stop the war, nor create conditions for either Assad or the insurgents to prevail. More likely, the grinding conflict will go on. Syria will become ghettoized with ethnic groups defended by local armed militias. Kurds and Christians will pay a dear price for fence-sitting, as the failed state fragments into cantons.
General Martin E. Dempsey, Chairman of the Joint Chiefs of Staff, struck a cautious tone at Congressional hearing last week. For sure, the U.S. military can degrade Syria's war-making capacity. After attacking Syria, however, it will face multiple threats including stateless adversaries motivated to defend sectarian interests across the Shiite Crescent.
(David L. Phillips is Director of the Program on Peace-building and Rights at Columbia University's Institute for the Study of Human Rights. He is a former Foreign Affairs Expert for the State Department's Bureau of Near Eastern Affairs).