President Trump's Syria Conundrum

The Trump Administration has been consistent on one thing: its priority in Syria is ISIS. Even though it retaliated for Assad's use of chemical weapons, its focus has been ISIS -- not Assad, and not Iran -- in Syria. Going back to the presidential campaign, Trump was certainly consistent in saying that he wanted to work with the Russians in Syria and that, too, now seems to guide the policy.

After the meeting between Presidents Trump and Putin on the margins of the G-20, Secretary of State Tillerson announced an agreement on a ceasefire in southern Syria. He spoke of it being a first step and said at the time that the Russians may be "more right on Syria" than we are. This was a remarkable statement given the unlimited bombing of civilian areas that the Russians have conducted and the message he was sending them, perhaps inadvertently, about our readiness to acquiesce in their approach.

It is easy to be skeptical about this policy. The Russians, after all, have agreed to several previous ceasefires or cessations of hostilities and have enforced none of them. When the Assad regime or the Iranians and their Shi'ite militias violated the understandings, the Russians did nothing. On the contrary, they have used their air power to provide air cover for the Syrians and the Shi'ite militias as they have extended their reach in the country. Could it be different this time? Could Putin have an interest in making this ceasefire understanding stick, and actually impose it on a regime that declares loudly that it seeks to "take back every inch" of the country?

Perhaps. Putin probably does have an interest in lowering Russia's costs in Syria. He faces an election next year, and he does not need the price of Russian involvement in Syria to go up. Moreover, he has achieved everything (and more) he hoped for in intervening in Syria. Russia now has an air base in Syria, something that even the Soviet Union did not achieve. It is expanding its naval facility at Tartus, turning it into much more of a functioning base. It has established an air defense umbrella in Syria that stretches into the eastern Mediterranean. And Putin has demonstrated that Russia is an arbiter of the conflict in Syria and increasingly in the region. Today, when it comes to security, every state in the area needs to reckon with and come to Moscow -- and if one looks at who now travels to see Putin from the Middle East, it is all the leading states. In fact, they seem to be going to Moscow more than they are coming to Washington DC.

In theory, therefore, Putin might have an interest in stabilizing the conflict in Syria and containing an ongoing war that could end up draining Russian coffers and imposing higher casualties. The problem is that at this point, the Assad regime with the manpower of Hezbollah and Iran's other Shi'ite militia proxies are not just consolidating their control but extending it in the Damascus suburbs, in Idlib province, and eastern Syria on the Damascus-Baghdad highway. They are fulfilling the Iranian desire to create a land bridge from Iran through Iraq and Syria to Lebanon, and the ceasefire in the Russian de-escalation zones serves their purpose for the time being. But what happens when the current consolidation-expansion is completed, and Assad and his Iranian partners/masters then turn their attention to gaining control of Syria's borders with Jordan and Israel? And, given the Iranians' desire to extend their leverage in the region, it is almost certain they will seek to do so.

The Israelis have already publicly expressed their opposition to the ceasefire because they see it as legitimizing the Iranian and Shi'ite militia presence in Syria and potentially close to their border. The Israelis have made it clear they won't let Iran open up a second front against them in Syria. Maybe this will deter the Iranians; at a minimum, they will test and probe to see just how serious the Israelis are. Unfortunately, they are far less likely to be deterred from trying to position themselves along the Jordanian border, convinced this will give them the means to destabilize the Hashemite Kingdom and threaten the Gulf States from yet another direction.

Unlike in the case of Israel, the ceasefire agreement is supposed to keep the Syrian regime and the Iranians 40 kilometers from the Jordanian border. That, however, depends on the Russians stopping the Syrians and Iranians. If the past is any guide, they won't, unless, of course, they decide that this will extend the conflict and increase their costs.

The Trump Administration could make it clear that there is a cost. If it was prepared to say the U.S. will enforce these ceasefire areas and buffer zones if the Russians don't, Putin would pay attention. Not only would it signal that the U.S. was going to be an arbiter of events in Syria -- something Putin seeks to avoid -- but it would also mean we would act to punish the Syrian regime for its transgressions.

One of Putin's objectives has been to show that the Russians stand by and protect their friends. He is not going to want to have to protect further Syrian efforts at expansion if it costs the Russians, and he is also likely to be leery of having the insurgency re-emerge after seemingly containing it. One way for the U.S. to punish the regime would be to resume lethal assistance to Syrian opposition groups. That may seem very unlikely after the Trump Administration has ended that assistance, but if the Russians appear to be retreating from the ceasefire agreement, this could be an option for the administration.

The irony for the Trump administration is that if it wants to defeat ISIS and not have it re-emerge, there must not be a vacuum left after the defeat of ISIS in Raqqa and its remaining pockets of control in Syria. Presently, the Iranians expect such a vacuum and are positioning themselves to fill it. If they do so, we can expect to see them once again introduce the kind of sectarianism and exclusion of Sunnis that produced ISIS in the first place.

The administration needs to focus on preventing such a vacuum by ensuring that Iran and the Shi'ite militias don't keep expanding their presence in Syria. President Trump needs to convey to Putin that cooperation in Syria depends on the Assad regime and the Shi'ite militias not expanding from where they are now; that we will punish violations of the ceasefire agreements if the Russians do not; and that while we will not seek to roll back the regime and the Shi'ite militias, we won't tolerate their establishing a presence and control in more areas of Syria.

President Trump and Secretary of Defense Mattis are clearly reluctant to get more deeply involved in Syria, but unless they are prepared to prevent the further expansion of the Iranians' and Assad's forces after ISIS's defeat, there may well be greater instability in the region and the re-emergence of the next incarnation of ISIS. If they want to prevent such a scenario from materializing, they need to establish limits now and make sure Putin understands them.

Dennis Ross is the counselor and William Davidson Distinguished Fellow at The Washington Institute and former special assistant to President Obama.