Is Ukraine heading for defeat?

The rhetoric is getting wilder and wilder. Ukraine's prime minister is warning that Russia will win the war unless the US provides the weapons Kyiv desperately needs, and that defeat for Ukraine would lead to the Third World War. Wow! I know it was intended as a wake-up call to Congress to pass the necessary legislation to get the $60 billion in military aid, but if it all goes wrong and the current legislative impasse continues into the summe, is the future for Ukraine and for the whole world as bleak as the Ukrainian prime minister is warning? My personal view is that although Vladimir Putin is pretty bad he is not Hitler. If he starts to invade the whole of Europe as some people are predicting, what would China do, for example? It would definitely not be in China's interest for there to be a European war, Third World War scale or otherwise. Beijing may have a strategic partnership with Moscow but would President Xi Zinping really want calamity in Europe? I don't believe it. So Beijing would be a constraining influence, one would hope. Also, however boosted Putin might be by a victory over Ukraine, he cannot want a major war with the whole of Nato. So, please, less talk of a Third World War.