The war in Ukraine reflects collisions in Russia-Ukraine relations, Europe-Russia relations, and U.S.-Russia relations.

Diplomacy could well come to occupy center stage for a president who relishes summitry.

Donald J. Trump will assume the U.S. presidency at a time of flux in South Asia. Afghanistan appears at risk of greater instability, Pakistan continues to harbor terrorists that attack its neighbors,…

Together, China’s rise and Trump’s reactions threaten to bury the liberal international order and limit Sino-American cooperation, and tensions could well spill over into other regions and global cha…