Defense In Depth
Why U.S. Security Depends on Alliances—Now More Than Ever
In the words of U.S. Secretary of State Rex Tillerson, the administration of President Donald Trump is currently “reviewing ways to confront challenges posed by Iran.” This most likely means looking for ways in which to curb Iran’s expansionism in the Middle East. But for any containment plan to be effective, Washington must examine Iran’s newly emerging strategy in the Levant and must understand that although Tehran still hopes to achieve regional hegemony in the long term, its current plan is to focus on obtaining and maintaining a predominant position in Iraq, Lebanon, and Syria. The bloody quagmire involving those three countries offers more opportunities to consolidate power than what would surely be a riskier confrontation in the Gulf, where Iran would have to contend with the United States and its allies. Success in the narrower approach, moreover, could ultimately strengthen Tehran’s hand against Saudi Arabia and those in the Sunni bloc.
General Qassem Soleimani, the commander of the Quds Force division within Iran’s Islamic Revolutionary Guard Corps (IRGC), is one of those in charge of executing the new policy vision. For the last three years, he has been kept busy setting up the building blocks for at least one, but more likely two, land corridors across the Levant (one in the north and one in the south), linking Iran to the Mediterranean. These pathways would traverse a distance of at least 800 miles from Iran’s western borders through the Euphrates and Tigris valleys and the vast expanses of desert in Iraq and Syria, providing a link to Hezbollah in Lebanon, and finally ending at the edge of the Golan Heights. The two corridors would serve as chains to move military supplies or militiamen when needed. Lately, a number of Iranian-sponsored Shiite militias have mentioned in public their efforts to move their fighters along these routes. Forces from the Lebanese militant group Hezbollah, for example, are present in Syria and in Iraq, while key Iraqi Shiite militias are currently in Lebanon.
The idea, according to several senior Iranian officials, would be to outsource the supervision of the corridors to proxy forces, such as Hezbollah and the various Shiite militias Iran sponsors in Iraq and Syria, in order to avoid using its own military forces to control the routes. (Iran has a long-standing aversion toward investing manpower abroad.) Tehran’s proxy militias would be able to field a force numbering 150,000 to 200,000 fighters, including 18,000 Afghani Shiites, 3,000 to 4,000 Pakistani Shiites, and small Christian and Druze militias. Some of these forces have already been deployed to various sectors along the envisaged corridors. Iran would also be able to recruit more Shiites—especially refugees from Afghanistan and Pakistan seeking employment and a cause.
The northern corridor would pass from Iran through the now Shiite-majority province of Diyala toward Kirkuk Province and the town of Shirqat to the east and link to Syria via the Tal Afar and Sinjar mountain districts. This means that Iranian convoys would reach Syrian Kurdish territories already reconnected to areas under control of Syrian President Bashar al-Assad. In order to move through this corridor, the Iranians would need to ensure that neither the Iraqi government nor the Kurdish forces farther west interfere. In view of growing Iranian influence over the Iraqi government and its armed forces, it seems very unlikely that there will be real opposition from Baghdad to their convoys. The same is true for the Kurds. The peshmerga, the military forces of Iraq’s two main Kurdish political parties, the Patriotic Union of Kurdistan and the Kurdistan Democratic Party, would be disinclined to halt Iranian troop movement that does not threaten their own interests. The Kurdistan Workers’ Party (PKK) forces in Sinjar have close ties to Iran, and in Tal Afar, pro-Iranian militias are already operating with U.S. consent. In Kurdish Syria, known among the Kurds as Rojava, Kurds governed by the Democratic Union Party (PYD) are under constant threat from Turkey, which considers the PKK and PYD terrorist groups and thus regard Iran as a friendly power.
The recent intensification of the Turkish-Iranian rivalry in the Levant did not lead, until now, to any on-the-ground friction. It will probably remain that way in the foreseeable future. Turkey’s President Recep Tayyip Erdogan seems to prefer rhetorical rather than real war against Iran. He denounces Tehran’s activities in the Levant, or what he calls “Persian expansionism,” but judging by Erdogan’s conduct so far, he would be hesitant to use his considerable influence over Iraqi Kurds, the Turkmen minority in Iraq and Syria, and Arab Sunni militias to try to foil the Iranian scheme.
The southern corridor would permit traffic from Iran to pass through the Shiite provinces of Iraq, incorporate the main desert highway of Anbar Province, and wind through eastern Syria before reaching Damascus. The main problem with this route is that Anbar’s predominantly Sunni population views Iran with suspicion and hostility. But most of the estimated 1.5 million Sunni inhabitants reside in four large cities—Fallujah, Haditha, Ramadi, and al-Qaim—that can be easily avoided by taking routes through the arid and sparsely populated countryside. It was in these same areas that Iranian-sponsored Shiite militiamen fought alongside the Iraqi army to defeat the Islamic State (also known as ISIS), and they still maintain some strongholds along the highway. In this regard, Iraqi security forces stationed alongside Anbar’s desert highway are not likely to object to convoys coming from Iran or its allied militias. The local Sunni tribes would be reluctant to ignite a conflict, especially one they could not win. Iran could urge, bribe, or coerce them into turning a blind eye to Iran convoys cutting through their turf.
Over the next decade, Iran intends to modernize its outdated military arsenal. This would gradually provide both the IRGC and the Islamic Republic of Iran Army (or Artesh) the mobile artillery, tanks, and other equipment necessary to consider forming, at some point, a long-range expeditionary force to reinforce their allied militias. With an upgraded air force, Iran could provide cover for ground troops moving along the corridors, either to assert influence over local political factions, tribes, and sects or to mass troops near the Israeli borders.
Once the battles raging in Syria and Iraq subside, Iran will most likely continue to develop its proxy militias in both states, in the same manner that it props up Hezbollah in Lebanon. In Iraq, the Iranian-sponsored militias, which are part of the Popular Mobilization Units, an umbrella of dozens of mostly Shiite militias, have already received official recognition and funds from Baghdad. In Syria, too, if Assad remains in power, Iran plans to incorporate its wide array of militias into a Basij-style volunteer paramilitary structure that would effectively be under Iranian control. These militias are intended to help preserve the pro-Iranian governments across the Levant and maintain the corridors by establishing a string of local domains and ad hoc alliances with local players along the routes.
The ultimate purpose of the corridors, however, is to expand Iran’s reach into the Golan Heights, with the goal of tightening the noose around Israel. The Iranians publicly express their keen interest in opening up the Golan front to their proxies, and high-ranking IRGC officers are engaged there now in the establishment of a new militia—the Golan Regiment—partly composed of Palestinians residing in Syria. Ahmed Jibril, the veteran leader of the Iranian-sponsored Popular Front for the Liberation of Palestine–General Command, has been advocating for such a move in the Golan Heights, a call that has also been echoed at various times by the official Syrian media. Such a tactic would extend the current frontline in Lebanon between Hezbollah and Israel all the way down to the Yarmuk River where the Syrian-Jordanian-Israeli borders meet. Leaders of some Iranian-sponsored Iraqi militias, such as al Nujaba, are already talking openly about their intention to move their forces to the Golan front. Israel has retaliated several times to attacks coming from that region, and one Iranian general was killed during those clashes.
In responding to Iran’s plan to secure influence in the Levant, the Trump administration should work with its regional counterparts to thwart Iran’s attempt to build these two corridors. Turkey, a NATO ally, should be encouraged to resist Iran’s efforts to dominate, through the corridors, the main trade routes serving large amounts of Turkish exports to the Arab world. The Kurds, both in Iraq and in Syria, should be provided military equipment to face the Shiite militias. Jordan should assist the Sunnis of western Iraq, as well as the Shamar Bedouin federation of the Syrian desert, which has traditional ties with the Saudis, in organizing their own forces. The United States should back Israel’s effort to prevent the Iranians from securing a foothold on the Syrian side of the Golan Heights. But above all, the United States should continue talking with Russia and insist that sooner rather than later, Syrian leader Bashar al-Assad will have to go.