Syrian President Bashar al-Assad signaled Tuesday that his government intends to escalate military efforts to crush the five-year-old uprising against his rule, saying the bloodshed will not end until he has regained control over all areas of Syria lost to the rebellion.

His tough words came amid indications that Russia is preparing to reengage in the war in support of Assad, almost three months after it threw its support behind a U.S.-backed cease-fire and announced it was withdrawing most of its military from Syria.

The violence has already been ticking up, with government and Russian warplanes conducting air raids over northern Syria in the past week and rebels launching an offensive to recapture territory south of the city of Aleppo. According to the Institute for the Study of War, Russia tripled the number of its airstrikes over a four-day period last week, to levels not seen since before the imposition of the cessation of hostilities in late February. […]