New Delhi, May 13 -- The war game scenario was this: One of NATO 's newest members, Sweden, was under threat by an unnamed country that was building up troops along the military alliance's eastern border. And in an unusual twist, non-NATO member Ukraine was there to advise on drone warfare - and delivered a critical warning to the alliance.

The Associated Press was allowed to witness the Swedish-led military exercise this week as Europe faces not only the threat of Russia but the wavering of NATO's most powerful member, the United States.

The war game that also involved U.S. forces played out with a real threat in mind. For months, Russia has ramped up sabotage including cyberattacks against critical infrastructure and disinformation ag...