The United States is once again changing its strategy in Syria. Only months ago, the country signaled that it was looking for an exit from the conflict once it had accomplished its main goal of severely degrading the abilities of the Islamic State. That prospect caused concern among its local partners in the Syrian Democratic Forces, who began to ramp up their overtures to the Syrian government as a fallback option in case of a U.S. departure. But according to new U.S. Special Representative for Syria Engagement James Jeffrey, the United States is now on course for a more indefinite mission. President Donald Trump reportedly agreed not to push for a U.S. exit and instead signed off on a concerted diplomatic and military effort in Syria extending beyond the counterterrorism mission. And the shift in focus is likely to complicate Russia's plans in the region....