An attack on Poland would immediately invoke NATO Article 5, drawing in the combined forces of continental Europe, the UK, the US and Turkey. The world wouldn't need to worry about it going nuclear, conventional forces would have the Russians back over the Belarusian border by lunchtime.
Gammelfisch said it better than I could, but what makes you think Trump would feel any type of responsibility to follow through with a treaty signed by a president that isn't him and was almost 100 years ago?
Mango Fucking Mussolini would abandon Poland like the British and French in 1939. Fuck Russia and the MAGAts, this German supports the European NATO members and especially our neighbors to the east. If the motherfucking Muscovites attack, I will request to be reinstated and do whatever I can to stop the filthy bastards.
This is what I fear will happen when Canada is annexed. The other NATO members will express outrage, but who's going to launch an invasion across the Atlantic against the most powerful armed forces in the world to liberate Canada?