The war is not going well and I could see how cutting the western support could force the Ukrainian loss. We have seen that when the front started crumbling during the period when the ammunition supply from the US was interrupted for half a year.

The west can definitely force Ukraine to sign a humiliating treaty, ceding land and freezing the conflict, there's plenty of leverage for that. If that happens, the days of Ukraine as an independent state are numbered - a new invasion will happen as soon as russians rebuild their forces, and this time it will be done right. People will continue to die even if the country gets erased from the map, just maybe not in the trenches, but in the torture chambers and prisons instead.