From marauding jihadists in Iraq to pro-Russian separatists in Ukraine and beheadings of Americans in Syria, a world in crisis has fanned perceptions of an overwhelmed U.S. president and contributed to a Republican sweep of U.S. midterm elections.

But the slide of public confidence in President Barack Obama and the takeover of U.S. Congress by resurgent Republicans will complicate, though not seriously undermine, U.S. foreign policy that is grappling with wars in the Middle East and Eastern Europe, and a more aggressive China in Asia.

Republicans rode to victory with a boost from the widespread view of an Obama White House beset by perpetual crisis. Broadcasts of black-clad Islamic State militants advancing in Syria or medical teams in white hazmat suits grappling with the Ebola epidemic played endlessly on TV news broadcasts, badly damaging Democrats at Tuesday's midterm elections.