Iran’s Islamic revolution, which brought Shias to power in 1979, and the Sunni backlash have fueled a competition for regional dominance. This timeline highlights Sunni-Shia tensions in recent decade…

The Democratic Republic of Congo has been subjected to centuries of international intervention by European powers, as well as its African neighbors. This timeline traces the role of the outside forces that have beleaguered eastern Congo since the end of the colonial era.

The Taliban surged back to power two decades after U.S.-led forces toppled their regime in what led to the United States’ longest war.

The nuclear arms race was perhaps the most alarming feature of the Cold War competition between the United States and Soviet Union. Over the decades, the two sides signed various arms control agreeme…

The United States' dependence on oil has long influenced its foreign policy. This timeline traces the story of U.S. oil development.