About the authors
Ilan Goldenberg is the Director of the Middle East Security Program at the Center for a New American Security.
Nicholas A. Heras is the Bacevich Fellow at the Center for a New American Security.
President Trump on April 6 said the U.S. military struck a Syrian military airfield in retaliation for a chemical attack on Syrian civilians that occurred April 4. (The Washington Post)

President Trump’s decision to launch missile strikes against Syria’s Shayrat airfield after a chemical weapons attack on civilians was an appropriate response to an act of unspeakable horror. Yet as analysts who have argued for greater U.S. military engagement to end the Syrian civil war, we find ourselves conflicted about the president’s decision: We fear there is simply no plan for what comes next.

To succeed beyond Thursday’s limited strikes, American leaders must decide on a clear set of objectives, a realistic desired final outcome, a theory of the case for how to get there and a solid understanding of the risks. We see three potential options for how the president could move forward.

The United States could pursue a limited strategy focused on one-off strikes in response to the Syrian regime’s use of chemical weapons. In that case, the strike on the air base from which this week’s chemical attack was launched will probably be enough. President Bashar al-Assad and his generals will get the message and stop using those types of weapons.

However, Trump may soon find this outcome dissatisfying. The regime will continue to terrorize civilians through airstrikes, artillery and surface-to-surface missiles against densely populated areas. It will continue to employ tactics such as starvation sieges and population transfers to tear communities apart.

Pictures of dead children and “beautiful babies,” as the president remarked, will continue to appear on television. And Assad’s forces and their Russian allies may up the scale of attacks to humiliate Trump and demonstrate the fecklessness of American military force. Thus, the pressure may grow on the United States to respond, and it may be hard for Trump to resist. The United States may slowly start to expand its objectives and escalate the conflict, and eventually find itself in a situation similar to Libya in 2012, where a limited civilian protection mission morphed into a full-blown regime change operation.

Alternatively, the administration could pursue a broader set of interests than strictly deterring chemical weapon use. These initiatives could, for instance, prioritize ending the Syrian civil war and closing the security vacuums that are the source of extremist attacks and massive refugee flows destabilizing American partners in the Middle East and Europe.

To achieve these objectives, the United States would threaten to launch more missiles on Assad regime targets unless Assad and his Russian allies stopped attacking civilians in opposition-held territory. The United States could target a wide array of facilities to compel Assad, such as weapons factories, major military bases, even ministries in Damascus responsible for the war effort. Using the threat of missile strikes instead of flying in manned aircraft to drop bombs is much less dangerous. The United States would not have to first destroy all of Syria’s air defenses — a highly provocative step sure to result in Russian fatalities, because Russian advisers help operate many of these systems. With the Russian and regime bombardment from the air stopped, the United States would then work with moderate armed groups in opposition areas to marginalize extremists and stabilize this territory.

This approach is risky. Russians are deployed throughout Syria, whether at regime bases or in a close advising role embedded with Assad’s forces on the front lines of the civil war. If the U.S. military inadvertently kills a significant number of Russians, tensions between the world’s two largest nuclear weapons states could skyrocket. The United States can try to warn Russia in advance of the targets it is striking, as it reportedly did with the strike this week, but the risks go up as the target lists become more expansive.

Moreover, this approach requires a viable moderate armed opposition that can serve as an effective local partner on the ground. Such groups exist in southern and eastern Syria but have become much weaker in the hotly contested northwest, where last week’s chemical weapons attacks occurred.

A final military option would be to pressure Assad from the south, where the United States and Jordan support a moderate coalition of armed opposition groups known as the Southern Front. In recent years, these forces have generally stabilized the areas of Syria bordering Israel and Jordan, and have fought hard against the Islamic State. But the Southern Front has also been restrained by the United States and Jordan, who have preferred a stable front near Jordan’s border and have threatened to cut off military support if the alliance moved too aggressively. If the restraints came off, this moderate rebel force could soon be bearing down on Damascus, putting huge pressure on the regime.

But this would require a major surge in fighting in an area that has been largely quiet the past few years. The regime would probably respond with the same scorched-earth tactics it has used elsewhere, and civilians would suffer. Moreover, the Southern Front may achieve catastrophic success and inadvertently topple Assad quickly, resulting in chaos. In that case, Jordan and Israel would feel the destabilizing effects of intensified fighting on their borders.

In the end, all of these military options are useless if they cannot be translated into a political outcome. The three military options outlined above can provide the United States with leverage in negotiations with Russia, Iran, Assad, Turkey and the Gulf States — but only if Trump has a clear view of the end he is seeking.

The most viable political goal is a Syria that remains whole as one nation, but with a governance model that would feature power devolved away from the central government to local actors who hold the territory in six different zones of control that now divide the country. This idea reflects the realities on the ground and has grown in support among experts as the war has dragged on.

Such an outcome would require a major diplomatic lift to mediate an arrangement between the Turks and Kurds in the north. The United States would have to come to a settlement with Russia and Iran on who retakes the territory currently held by the Islamic State and al-Qaeda. And we would need to assure Israel and Saudi Arabia that Iranian influence in Syria will be contained.

Unfortunately, it is this final and most important part of any plan for Syria — the political plan — which we are most concerned about when viewing the Trump administration’s approach.

We disagreed with former president Barack Obama when he insisted on too much certainty before taking any action in Syria. War does not always work that way: Sometimes, you have to take risks and jump into the breach.

But when it comes to Trump, we have yet to see any indicators that he has a broader political approach in mind. Less than a week ago, his team was arguing that removing Assad is unrealistic and that, instead of focusing on the civil war in western Syria, they would prioritize the effort in the east against the Islamic State. The president himself spent two years campaigning on opposition to deeper U.S. involvement in the Middle East, and his team has yet to engage seriously in any of the diplomatic processes surrounding the Syrian conflict — including the intensive talks in Astana, Kazakhstan, hosted by the Russians, or a major international Syria reconstruction conference held this past week in Brussels. And — most concerning of all — they have de-emphasized diplomacy, aid and reconstruction as tools of American foreign policy by calling for dramatic financial cuts for all these efforts and making clear to the international community that the United States is stepping back from coordinating these efforts.

If the United States is to turn the limited tactical strikes in Syria into a real strategic gain, the Trump team will have to change its approach, and focus not only on winning the war but also on winning the peace.