Not being a fan of Joe Biden, this is difficult to say but, he has made the correct call on sending 5000 troops to Ukraine if he really does it. Can 5000 troops stop a Russian invasion, of course not. During the cold war the Berlin brigade could not have stopped a Soviet invasion, but US troops would have been engaged so it would be war with the US. The problem is at that time our leadership was perceived by our enemies as strong enough to go to war. After the Afghanistan debacle and decades in government that showed he was a dove will Russia take him seriously. Seeing his weakness will our allies be willing to follow. Time will tell.