The end of summer. It means back-to-school shopping, tearfully ended beach-borne romances, Labor Day barbecues—and, it would seem, the increased likelihood of new Russian adventurism. As if Moscow weren’t satisfied with the game in Ukraine, the last month has seen a flurry of reports about its ever-expanding military involvement in Syria.

One report has even alleged that Russian pilots are gearing up to fly missions alongside the Syrian air force, dropping bombs not just on ISIS but on anti-Assad rebels who may or may not be aligned with the United States or its regional allies.

Several sources consulted for this story said the Pentagon is being unusually cagey about Russia’s reinvigorated role in Syria. A former U.S. military officer told The Daily Beast, “I’m being told things like, ‘We really can’t talk about this.’ That indicates to me that there’s some truth to these allegations.” […]