My point is that after the Great Powers granted Hitler the Sudeten, the implication was that that was it, and that's why the invasion of Poland prompted a declaration of war.

NATO may be strained to the breaking point soon. Already in many NATO countries the US administration is seen as the greatest threat to world peace by public opinion [this has been brought out by polls repeatedly]. I wonder what the governments think, if they agree they keep it private. The US might overstretch itself to the point of being forced to request NATO assistance for a war opposed by its NATO allies, and then demand that assistance.

Nothing is 'mere'. — Richard P. Feynman