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.

Negotiations between the United States and North Korea have proceeded in fits and starts for decades. But they have failed to halt the advance of North Korea’s nuclear and missile programs.

The Kurds are one of the world’s largest peoples without a state, making up sizable minorities in Iran, Iraq, Syria, and Turkey. Their century-old fight for rights, autonomy, and even an independent …

The United States and China have one of the world’s most important and complex bilateral relationships. Since 1949, the countries have experienced periods of both tension and cooperation over issues …