The US has announced that it will send 2 sets of Patriot missile systems to Poland to protect against any potential attacks during the ongoing Russian invasion of Ukraine.
America has stated that this is not an offensive move and is in line with Article 5 of the Washington Treaty. Reiterating that they don’t support offensive behavior.
This moves come as America and Poland are attempting to thread the needle on a deal to move 28 MiG-29 fighters to Ukraine to help protect their air space.
Russia is almost certain to see this as an act of aggression, potentially war. However, with them currently involved in an ongoing invasion into a sovereign country, it seems that they may not be in a position to make complaints about weapon swapping between allies.