The United States and Israel are awaiting a threatened “significant” Iranian response to the attack on its consulate in Syria, but this is just part of a much larger challenge: Iran is accelerating its long-standing goal, a push for regional hegemony. The key manifestation is its current push to get U.S. forces out of Iraq and Syria. Among other things, Tehran is using its proxy militia leaders and pro-Iran-Islamist parties to oblige Iraqi prime minister Mohammad Shia’ Ali Sudani to push Washington for a timetable on full U.S. military withdrawal. 

Sudani will meet President Biden on April 15. In advance of this, he has already conveyed that he wants the meeting to focus on the withdrawal. Iran knows that a U.S. withdrawal from Iraq and the loss of the accompanying logistics will make the U.S. military presence in Syria unsustainable. 

Sudani must be aware that the withdrawal from Iraq will further strengthen Iranian domination of his country, to which our forces serve as the only effective deterrent. However, his ability to operate is limited. He does not have the backing of a political party or security forces, making him a mere figurehead in a government dominated by those two forces. His position is largely dependent on the will of pro-Iran Shia Islamist parties and pro-Iranian militia forces. 

Sudani has maintained good relations with U.S. diplomats and military officials. He is the friendly face of the pro-Iran Islamists and proxy forces vis-à-vis the United States and the region. But it’s important to remember that he is not in charge. At most, he can convey messages from those in charge and act as a mediator. 

The Iranian leaders, proxy militias, and parties are putting Sudani in an uncomfortable position: He is being pressed to push for a definitive timeline for the withdrawal of U.S. forces, or he risks losing his job, which he seems determined to keep. At a minimum, he must appear to be seriously trying to accommodate their instructions. He will want the Biden administration to appear to be earnestly considering negotiations for a withdrawal.

The continued presence of U.S. forces presents a formidable obstacle to one of the Iranian regime’s major strategic regional objectives: the domination of the Fertile Crescent, Iraq, Syria, Lebanon, and the Palestinian areas. Tehran aims for a continuous and unhindered land corridor to the Mediterranean. 

Local obstacles to Iran’s ambition will remain. These obstacles include the Kurdistan Regional Government, some Sunni Arabs, and even a few patriotic Shia groups who oppose Iran’s domination of their country—although they have not taken a public position against the withdrawal, fearing reprisal and assassination by Tehran’s proxy militias. They are closely monitoring the United States’ response. We can work with these forces to oppose Iranian expansionism. However, a complete U.S. withdrawal would remove the most important barrier to Iran’s aggressive goals and create a vacuum into which Iran will insert itself. A withdrawal will also affect the calculations of many other players as they assess the future balance and order in their region. 

Obviously, Iran’s domination of the Middle East is not in the U.S. interest. Its regime is hostile to the United States, supports terrorism, pursues nuclear weapons, is building ever-longer-range missiles to deliver conventional and eventually nuclear weapons, and has set aside mutual suspicions to partner with our global adversaries, China and Russia. It would be a mistake to facilitate Iran’s domination of the Fertile Crescent by submitting to Iran's demand and withdrawing from Iraq and Syria. If we refuse, however, we must be prepared for Iran to increase the pressure and likely instruct its proxy militias to attack our forces in Iraq or in both countries. 

It’s vital that we review and make needed adjustments to our policy and posture to effectively deter this threat. Doing so must include the following four steps:

First, we must strengthen deterrence.

Responding by attacking their proxy forces is inadequate because, to Tehran, the lives of Iraqi, Syrian, Lebanese, or Yemeni militias are cheap and expendable. We would only be providing Tehran with an opportunity to test its weapons and operational concepts. Simultaneously, doing so imposes significant costs on us, financially and physically. Effective deterrence requires that we make the militias’ actions a problem for Iran. We need to clarify to Iran that a resumption of attacks by their proxies against us—our forces, including bases and naval ships in the region – will result in neutralizing Tehran’s high-value targets both in the region and inside Iran. 

Second, we must clearly convey to Iran that a resumption of proxy attacks will result in a strengthening of U.S. sanctions similar to those implemented during the Trump administration. Those sanctions were significant and included the oil and non-oil sectors, impacting more than 700 persons and entities. They were very costly for Iran, and Tehran fears their restoration.

Third, we must increase our political pressure on the Iranian regime by focusing on its vulnerabilities. Political oppression and economic mismanagement have made the theocratic government odious, causing it to fear a popular revolution or a coup by elements of its own security apparatus. The regime cannot sustain itself indefinitely. We can speed its demise through effective programs that expose its corruption and waste of resources through support for terrorist and extremist groups and that highlight the widespread opposition within the country. The Iranian people are not hostile to the United States. Indeed, perhaps nowhere in the Middle East is the United States more popular than in Iran. Also, the huge and successful Iranian diaspora community in America can be a valuable asset for the country’s economic and political development and a bridge between the United States and Iran.

Fourth, as we return in earnest to the Indo-Pacific, we must encourage regional states to strengthen their military capabilities and cooperate to oppose Tehran’s continued efforts at hegemony. Two critical elements in this effort are normalizing Saudi-Israeli relations and strengthening the U.S.-Saudi mutual defense treaty, and getting this back on track should be a high and urgent priority. 

The Iranian regime is an ambitious but also shrewd, calculating, and risk-averse player. Tehran will continue to increase its domination of Iraq and progress towards regional domination if it is allowed to do so. We need to push back and affirm that we don’t intend to let them succeed. 

Zalmay Khalilzad was the twenty-sixth U.S. ambassador to the United Nations (2007-2009) and the U.S. Ambassador to Iraq (2005-2007). Follow him on X: @realzalmayMK.

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