For anyone whose really interested in what Becker said, go to the 1 hour and 24 minute mark and watch the whole section. Becker never says that he's opposed to multipolarity, but that multipolarity as an end all be all is not what socialists should strive for. He asks the question "How can we make radical change in America by saying 'Vladimir Putin is our leader?', which is a very salient point. He goes on to say that we should strive for socialist leadership in all of our countries. What is so off about that? Seriously?
The point about the WW1 and multipolarity is making the point that multipolarity alone doesn't end war. Multipolarity between capitalist powers is still destructive.
Rainer Shead is really good at finding convenient quotes from revolutionaries and diluting it to hell and back. He cites Kim il Sung saying “The differences of state socio-political systems, political views or religious beliefs can by no means be an obstacle in the way of joint struggle against U.S. imperialism”, but just thinking about it for like 20 seconds, this obviously wouldn't mean supporting reactionary states against the US for the pure sake of it. Would Kim il Sung have supported Hitler? Obviously not.