The two-year-old war in Ukraine—which is far from deadlocked—could pivot dramatically in the coming months. U.S. decisions will play a decisive role.

With the demise of the Islamic State, a revived al-Qaeda and its affiliates should now be considered the world’s top terrorist threat.

Reports that China has stepped up efforts to gain influence in foreign political systems have sparked concern in Australia, New Zealand, and other states amid signs that the campaign may be shaping d…

North Korea’s test of an intercontinental ballistic missile during the week of the Hamburg summit injects an air of crisis into an already tricky set of meetings.