The old world has to die so that a new one can be born. Change is painful, but stagnation is death.

Leftists who still have faith in the current global order are disappointing. I don't know why you expect anything from liberals, though. Liberals are, for all intents and purposes, guardians of the status quo. Some of them might support things like minor reforms, but 'actual' leftists and self-proclaimed liberals operate in different realities.