As 2018 came to a close, it looked as if the Syrian conflict would continue along the same path. It seemed that the regime of Bashar al-Assad, with Iranian and Russian help, would win its battle against the opposition. The war against the Islamic State would approach the finish line. Foreign actors would maintain a fragile equilibrium in various parts of the country: among Israel, Iran, and Russia in the southwest; Russia and Turkey in the northwest; and the United States and Turkey in the northeast. But with a mid-December phone call to Turkish President Recep Tayyip Erdogan announcing the withdrawal of U.S. troops, Trump upended that balance; increased the odds of a bloody conflict involving Turkey, its Syrian allies, Syrian Kurds, and the Assad regime; and, in so doing, potentially gave the Islamic State a new lease on life by fueling the chaos on which it thrives.
The Trump administration’s earlier policy of indefinitely retaining a military presence in Syria was always of questionable value. It was unclear how 2,000 U.S. troops could curb Iranian influence or create meaningful pressure on the Assad regime. The fight against the Islamic State is not over, but it need not require maintaining U.S. troops on the ground. That said, a precipitous withdrawal presents one major risk: it will leave the People’s Protection Units (YPG)—the Kurdish-dominated armed group that sided with U.S. forces against the Islamic State and now controls roughly one-third of Syrian territory—perilously exposed.
The YPG could now face an attack from Turkey (which considers it a terrorist organization due to its affiliation with the Kurdistan Workers’ Party, or PKK) or by the Assad regime (which aims to reassert control over the entirety of the country, including the oil-rich northeast). Should disorder ensue, the Islamic State could seize the opportunity to stage a comeback by regrouping and recapturing some of the territory it has lost over the past two years. In short, the real question for the United States should not have been whether to stay or go, but under what timetable and what conditions to withdraw.
Both the United States and Russia should have an interest in preventing an all-out scramble for the territory abandoned by the United States because it could revitalize the Islamic State and because (from Russia’s perspective) it could result in Turkey controlling more of Moscow’s ally’s land. Averting this scenario will require Washington and Moscow (separately or in tandem) to persuade Turkey not to launch an assault on YPG-held territory, to persuade the YPG to lower its armed profile, and to facilitate a deal between Damascus and the YPG that entails the return of the Syrian government to the northeast coupled with a degree of Kurdish self-rule in the area. Such an outcome would simultaneously allow Syria to restore its sovereignty, reassure Turkey by limiting YPG authority and firepower, and protect the Kurds from military attack. It might be too late to achieve this goal. It is not too late to try.
In a world with fewer rules, the only truly effective one is knowing what you can get away with. The answer today, it turns out, is: quite a lot.
As the era of largely uncontested U.S. primacy fades, the international order has been thrown into turmoil. More leaders are tempted more often to test limits, jostle for power, and seek to bolster their influence—or diminish that of their rivals—by meddling in foreign conflicts. Multilateralism and its constraints are under siege, challenged by more transactional, zero-sum politics.
Read the original text at Foreign Policy.