President Putin’s sweeping moves to shift government power reinforce his own claim to leadership beyond 2024, but also set in motion competition for influence throughout Russia.

The collapse of the Cold War–era nuclear arms treaty signals trouble for U.S.-Russia relations, European security, and nonproliferation efforts.

The first summit between Joe Biden and Vladimir Putin eased some of the tension in the fraught U.S.-Russia relationship. It also laid bare the difficult path ahead to resolving differences on many is…

Scientists say the rain forest is approaching a critical tipping point at which the damage is irreversible.

The main battle tanks that the United States and Germany have agreed to provide Ukraine will help its forces punch through Russian fortifications and retake lost territory.