Defense In Depth
Why U.S. Security Depends on Alliances—Now More Than Ever
It’s hard to get tough on Iran. U.S. President Donald Trump’s recent announcements that he would decertify the Iranian nuclear deal (the Joint Comprehensive Plan of Action, or JCPOA) and expand sanctions against Iran’s Islamic Revolutionary Guard Corps (IRGC) testify to this fact. With these two moves, the Trump administration has expressed its dissatisfaction with the Iran policy it inherited from former President Barack Obama. At the same time, the administration has betrayed its inability (or unwillingness) to dramatically alter the United States’ overall strategy toward Iran. The recent announcements might make the U.S. approach to Iran marginally more assertive, but they will do little to change Iran’s behavior.
The Trump administration is realizing that changing Iran policy is difficult—not because Washington’s problems with Iran are unclear but because they cannot be addressed without changing the United States’ broader policy in the Middle East. In particular, if Washington does not rethink its strategy toward Syria, U.S. Iran policy will remain ineffective.
The United States has several strategic interests in the Middle East. Among them are ensuring the security of Israel and providing assurance to Washington’s Arab allies (including Saudi Arabia, Jordan, and the United Arab Emirates), which it does primarily through a sustained maritime presence in the Persian Gulf. Iran is the main threat to all of those allies, and Tehran’s militant clients (including Hezbollah, Iraqi militias, and the Houthis in Yemen) are the spear tip of that threat. Deterring Iran and its proxies is thus central to U.S. objectives in the Middle East. The United States is further committed to stabilizing Iraq, defeating the Islamic State (ISIS) in Iraq and Syria, and combating ISIS and al Qaeda affiliates elsewhere in the region. Washington has also played a supporting role in the Saudi-led campaign against the Houthi rebellion in Yemen.
Iran’s regional strategy is more streamlined. It is centered on countering the United States and its allies. Tehran wants U.S. forces out of the Persian Gulf and out of Iraq and Syria after the war against ISIS is over. Iran does not accept the existence of Israel as a Jewish state and is the main sponsor of anti-Israel militancy in the region. It wants to defeat the rebels in Syria and ISIS in Syria and Iraq and afterward to maintain a lasting security footprint in both countries through its local clients. More broadly, Tehran seeks to create a pro-Iranian bloc, stretching from Iraq to Lebanon, to stand against the United States and its Arab allies. Iran has also invested in the Houthi rebellion in Yemen, both to expand its influence in the Arabian Peninsula and to distract its adversaries, Saudi Arabia and the UAE, from the Syrian and Iraqi conflicts.
There is a paradox at the heart of Iran’s regional strategy: Tehran wants to expel the United States from the Middle East, but its behavior is largely what keeps U.S. forces there. Indeed, Iran’s harassing naval operations in the Persian Gulf, support for militant clients such as Hezbollah, and repeated ballistic missile tests since the nuclear deal have perpetuated Washington’s perception that Iran is the leading threat to its allies and the stability of the Middle East. Far from discouraging U.S. interest in the region, this behavior has served as a constant reminder of Iran’s hostile intentions and of the need to deter Tehran.
Deterring Iran, however, has not proved easy. The wars in Iraq, Syria, and Yemen have created opportunities for Iran to expand its influence across the region. In each country, the power of Iranian clients has grown, giving Tehran a leading role in their conflicts and an outsize stake in their futures.
Iran’s greater strategic clarity has enabled it to respond more quickly and decisively than the United States to shifting regional dynamics, as in the conflicts that followed the Arab Spring. In Syria, for example, the Obama administration spent four years neither fully committing to the rebels nor staying out of the conflict, whereas Iran was all in from the beginning in support of Syrian President Bashar al-Assad and has never wavered in its position. Iran’s support for Assad could have helped crystallize the United States’ commitment to the rebellion, if not for three factors: first, more direct intervention in Syria would have been politically unpopular at home; second, the rebellion gradually came to be dominated by Sunni extremist groups; and third, after the Hassan Rouhani was elected president of Iran in 2013, the Obama administration entered into serious negotiations with Tehran over its nuclear program. A U.S. military intervention against Assad risked empowering extremists in Syria and would have involved fighting Iran’s clients, thereby jeopardizing the nuclear talks. (It would have also put U.S. troops in harm’s way and cost a lot of money.)
In other words, there were sensible reasons for the United States to mostly stay out of the fight in Syria. But this relative inaction helped enable the rise of ISIS, the expansion of Iran’s security role, and, later, Russia’s entry into the Syrian war in September 2015. Moscow’s intervention was particularly limiting for Washington. It made escalation more dangerous, which benefited Iran, whose allies fell under the umbrella of Russian military power. Moscow’s involvement shifted the momentum in the war to Iranian and pro-Assad forces, which have made steady gains against the rebels in the two years since.
The wars in Iraq, Syria, and Yemen have created opportunities for Iran to expand its influence across the region.
The war against ISIS in Iraq further muddied U.S. strategy by thrusting Washington and Tehran into a de facto alliance in support of Baghdad. Unlike in Syria, where U.S. and Iranian interests clearly diverge, in Iraq both countries back the government and have committed troops and resources to defeat ISIS. Although U.S. forces do not coordinate with Iran or with Iranian-backed groups, both coordinate with the Iraqi government and military. The United States and Iran share the same immediate goal of defeating ISIS and preserving the unity of Iraq, which has put them on the same side of the Kurdish independence question as well.
The two countries’ common interests end there. Although U.S. troops in Iraq have been crucial in the war against ISIS, Iran and its allies don’t want them to remain in the country after the war. Iranian proxies fought U.S. and coalition forces during Operation Iraqi Freedom and have promised to target U.S. troops if Washington takes military action against Assad or if U.S. forces remain in Iraq after the defeat of ISIS.
Since the war against ISIS began, Iran’s ability to use its proxies to target U.S. troops has been its main source of leverage against the United States. Washington has had to take these threats seriously, knowing that any move against Iranian interests, in Syria or elsewhere, could put U.S. forces in Iraq at risk. Iran has its own incentives not to escalate with the United States in Iraq—it wishes to fully defeat ISIS, prevent discord with Baghdad, and avoid a conflict with the U.S. military—but Washington has had to assume that Tehran’s thinking could change if it perceived a threat to its interests.
As an outsider, Trump had a clean slate when he arrived in Washington. Already inclined toward improving relations with Moscow, he could have seized the opportunity to clarify U.S. Middle East policy. In theory, for example, Washington could have left Syria to Russia. This would have allowed the United States to focus on fighting ISIS in Iraq and lowered tensions with Iran. Iran, Russia, and Assad would have welcomed it; Washington’s European and Arab allies, as well as Turkey, would have gotten used to it.
But abandoning Syria to Iran was never a realistic choice, because doing so would have gone against long-standing U.S. interests and those of U.S. allies, especially Israel. Over the last couple of years, Iran and its clients have become increasingly focused on establishing a presence along Syria’s border with Israel, which they wish to use to exert pressure on Israel. This presence would increase the risk of a conflict (intentional or not) between Israeli and pro-Iranian forces, which in turn could lead to more conflict and further destabilize the region.
Perhaps sensing these limitations, the Trump administration has largely followed Obama-era policy and left Iran unchallenged in Syria. It has, however, made a point of increasing the pressure on Iran more broadly. Decertifying the JCPOA and extending sanctions on the IRGC are the most concrete steps in that effort. Yet such pressure won’t affect Iran’s position in the Middle East, which means that it won’t address the United States’ main problems with Iran. The JCPOA dealt with one of those issues—Iran’s attempts to acquire a nuclear weapon—and undermining it will further complicate Washington’s Middle East and Iran policies. With UN Security Council sanctions now gone, the nuclear deal is one of the United States’ most important points of leverage with Iran. Dropping it would abandon that leverage.
Although putting more pressure on the IRGC makes sense (particularly given its aggressive behavior since the signing of the JCPOA), that could be done while keeping the nuclear deal intact. Imposing sanctions on the IRGC while decertifying the deal has obscured the United States’ intentions. Instead of building consensus against Iran’s destabilizing activities in the Middle East, Trump’s unilateral decertification of the deal has diluted the case against Iran. It has made the United States appear spiteful and untrustworthy, not only to foreign governments but also to the Iranian people. Tehran looks reasonable and responsible in comparison.
If the United States wants to push back against the IRGC, it should target the source of the group’s strength: its regional footprint.
If the United States wants to push back against the IRGC, it should target the source of the group’s strength: its regional footprint. Syria is the place to start. This does not mean military intervention or escalation on behalf of the rebellion—that ship has sailed. Rather, it means a vocal and consistent reassertion of U.S. and allied interests regarding Syria’s future. At the very least, such a future cannot include a lasting security presence for foreign militias along Syria’s southern border. If such a presence were to take hold, it would likely lead to further conflict with Israel that could extend to Lebanon as well. To avoid that outcome, the United States will have to take the lead in ensuring that Syria’s post-ISIS transition does not destabilize the region. Doing so will require robust diplomatic efforts with Israel, Jordan, Russia, and Turkey to ensure that Iranian-backed groups are not allowed to use Syria as a base for cross-border operations against any neighboring state. This would clarify the United States’ chief concerns in Syria and provide the basis for a more coherent and effective strategy toward Iran.
U.S. policy toward Iran cannot be simply negative. The United States should encourage and reward compromise. Iran has a role to play in the region, and it has ties to Syria and Iraq that cannot be wished away. Iran’s legitimate activities in areas such as trade, diplomacy, and commercial investment should be respected, just as its covert operations and attempts to destabilize neighboring states should be firmly opposed. Leaving the JCPOA would only further harden Iran’s reticence toward compromise and not help counter its problematic activities in the region. Engineering a confrontation with Iran might be attractive in some corners of Washington, but most observers see folly in such a wish. Equally spurious is the notion that an unchecked Iran will somehow prove to be a steward of peace and stability in the region.
In other words, U.S. strategy and that of regional allies toward Iran should be based not on a maximalist approach but on achieving the most important goals of deterrence: keeping Iran free of nuclear weapons, preventing its clients from gaining a foothold on Syria’s borders, and countering Tehran’s aggression in the Persian Gulf. To accomplish that, the United States needs tough diplomacy backed by military power, and it needs to commit itself to the agreements it has already made.