SYRIA

After nearly seven years of war, President Bashar al-Assad’s regime has the upper hand, thanks largely to Iranian and Russian backing. But the fighting is not over. Large swaths of the country remain outside regime control, regional and international powers disagree on a settlement, and Syria is an arena for the rivalry between Iran and its enemies. As the Islamic State is ousted from the east, prospects for escalation elsewhere will increase.In eastern Syria, rival campaigns by pro-regime forces (supported by Iran-backed militias and Russian airpower) and the Kurdish-led Syrian Democratic Forces (the SDF, backed by the U.S.-led anti-Islamic State coalition), have forced an Islamic State retreat. In Syria and Iraq, Islamic State remnants have retreated into the desert to await new opportunities.

For the regime and the SDF, the fight against the Islamic State was a means to an end. The two aimed to capture territory and resources, but also to build on those gains — the regime by consolidating control; the Kurds by pressing for maximal autonomy. Thus far, the two sides mostly have avoided confrontation. With the Islamic State gone, the risks will increase.

The east is also perilous due to wider U.S.-Iran rivalry and the close proximity of these rival forces. Iranian gains, particularly the corridor linking regime-held parts of Syria to government-controlled Iraq, could provoke the U.S. to attempt to block what it views as a dangerous land bridge from Iran to the Mediterranean. Iran might target U.S. forces to retaliate against U.S. actions elsewhere or to push the United States out altogether.

In the southwest, Israel could view Iran-backed militias operating on and near the Golan Heights as a direct threat and take military action to push them back. Whether Moscow can prevent any Iranian or Hezbollah presence there, as it has pledged to do, is unclear. Israel may take matters into its own hands, striking Iran-allied forces. That pattern — prodding by Iran, pushback by Israel — could last for some time. But a wider confrontation is only one miscalculation away and could quickly spread beyond Syria, to Lebanon.

One of the gravest immediate dangers, however, is the possibility of an offensive by the Assad regime in Syria’s northwest, where rebel-held areas are home to some 2 million Syrians and into which Turkey has deployed military observers as part of a de-escalation deal with Iran and Russia. Regime and allied forces appear to have shifted some attention from the east to those areas, placing that deal under stress. A regime offensive in the northwest could provoke massive destruction and displacement.