Obama Faces a Crossroads

President Barack Obama came into office with a single, driving foreign-policy principle that shaped his approach to international crises: Avoid another protracted war like those in Iraq and Afghanistan.

Friday’s terrorist attacks in Paris, which killed at least 129 people, present Mr. Obama with a fundamental test of whether the approach is sustainable.

With one year in office remaining, the president faces pressure to escalate what is now seen as a global, rather than regional, fight against Islamic State militants, whom France accused of carrying out the attacks. Ho