WASHINGTON — While in office, former President George H. W. Bush once plaintively asked, “What is it about August?”

Indeed, this sultry month usually associated with the doldrums of summer has burdened modern presidents with personal, domestic or international crises. And for President Barack Obama, who returned to Washington Sunday from a two-week Martha’s Vineyard vacation, what remains of the August calendar looks perhaps more daunting than when he left.

Islamic militants personalized their fight in Iraq and Syria by executing American journalist James Foley. Russia escalated tensions in Europe by moving artillery and troops on the Ukrainian border and pushing a convoy into the former Soviet republic without Kiev’s approval. And a Chinese fighter jet provocatively buzzed a Navy plane in international air space.

His arrival back in the nation’s capital came with one positive note — Sunday’s release of an American freelance journalist who had been held hostage by al-Qaida affiliates in Syria.

Still, Obama faces his own self-imposed end-of-summer deadline for how to sidestep Congress on changes to U.S. immigration policies.

And while racial tensions in Ferguson, Mo., over the police killing of an unarmed young black man have subsided, the St. Louis suburb remains under the White House’s wary gaze. Amid all that, he’ll give a speech to the American Legion in Charlotte, North Carolina, on Tuesday and raise money for Democrats in New York and Rhode Island on Friday.