Trump envoy warns America could 'kick Russia's a*s' on the battlefield in the event of all-out war and says Putin's troops 'couldn't march to Berlin or anywhere else'

NATO could spark all-out war with Russia if it shoots down drones over Ukraine, Moscow warns as Europe bolsters its borders amid invasion fears

Robodogs, laser beams and drone-zapping microwaves: The weapons that will decide the wars of the future