European natural-gas prices plunged after the U.S. and Russia agreed to start talks to end the war in Ukraine, raising prospects that the Kremlin’s flows to the continent will resume.

Defense Secretary Pete Hegseth hammered home a message upon arrival at NATO headquarters Thursday that allies need to show ...

Russia’s invasion of Ukraine has sent its defense spending skyrocketing, and is raising fears it will attack NATO next.

Deterring Russia from re-invading Ukraine, once this war ends, could require 150,000 troops and American help with air cover, ...