You're making two arguments it seems, 1. Who is enforcing the arrest warrant against Putin, which I don't get, how should Europe or an African or Latin American country enforce the warrant enforce the warrant without Putin travelling there? I seriously doubt Putin would travel to a country where risks arrest. Or are you suggesting countries should invade Russia to arrest Putin. I don't see anyone including the US (thankfully) doing that. AFAIK that would also constitute a violation of international law (mind you many western countries really only care as long as it suits them, the whole Israel situation being a clear example). 2. The question if Europe could defend itself against invasion without the US. Defend against whom I have to ask, the only possible aggressor would be Russia, but Russia is struggling with their Ukraine invasion, a much smaller, less trained, less equipped force than Nato even without the US. The suggestion that Russia is in any position to threaten Europe is absolutely laughable. The only way that would happen is using nuclear weapons, and once we go down that path the whole world is f*ckd.