Trump is now offering assurances that U.S. troops won’t be sent to help defend Ukraine against Russia after seeming to leave ...

There was little concrete progress Monday on the obstacles to ending the war — a deadlock that likely favors Russian ...

Opinion: Washington has underinvested in air and missile defense for too long and is now facing the consequences.

Gen. David Allvin will retire this November after two years as the service’s highest-ranking uniformed officer.

Outer space has emerged as the world's next battlefield, demonstrated by recent cyberattacks on satellites blamed on Russia.

The event drew participants from U.S. industry and allied nations to consider what technologies might be needed to operate in ...