There's a huge difference between invading a NATO member and invading a non-NATO member. And ultimately I don't think Russia has the capability to continue invading more countries with or without the US' opposition, this war has been a nonstop embarrassment for them.
If Poland France and the UK are more invested in opposing Russia then one would think that the Ukraine wouldn't be entirely reliant on the US to support it. This is the fundamental problem with the proxy war in the Ukraine, the people pushing for it talk about it as if the fate of the European continent rests on the fulcrum of the Ukraine and yet the other European countries hardly seem to care.
If Poland France and the UK are more invested in opposing Russia then one would think that the Ukraine wouldn't be entirely reliant on the US to support it. This is the fundamental problem with the proxy war in the Ukraine, the people pushing for it talk about it as if the fate of the European continent rests on the fulcrum of the Ukraine and yet the other European countries hardly seem to care.