Syrian President Bashar Assad is taking advantage of the U.S.-led coalition’s war against the Islamic State group to pursue a withering air and ground campaign against more mainstream rebels elsewhere in the country, trying to recapture areas considered more crucial to the survival of his government.

As U.S. and allied jets swoop freely over towns and cities under control of extremists in northern Syria, the Syrian army has scaled back its air activity over areas of IS control, doing as little as possible there to avoid confrontation. Instead, Assad’s troops are now focusing their energies on the country’s two largest cities, Damascus and Aleppo.

“Whereas previously the Syrian regime had some interest or some level of obligation to take direct action against ISIS, to the extent that the American military is now doing this, the Syrians don’t have to do it,” said Christopher Harmer, senior naval analyst at the Washington-based Institute for the Study of War. […]