The US isn't that powerful in the UN General Assembly. The US could veto a reform in the UN SC, but that would be very embarrassing. It would be a huge victory, if the EU could convince other countries in the UN GA to vote for a reform, but it failed so far.
Ergo: I disagree with the notion that the US sets the international agenda despite its "stupidity" because it is more powerful than the EU. Rather: I think the problem is that the EU can't get organized.
Rather than discussing how to change that, ETB and other Europeans constantly criticise the bad US who prevent peace and progress etc.
Chirac, Blair and others love to strut on the world stage and appear important, forgettign each time that the only way that they ever get anything done is when they find a common position, which they've found extremely hard to do.
Part of it is the toxic relationship between the two men, part of it is outsiders who alos enjoy playing them off one agaisnst the other (but that works only because our European leaders let them and play along), and part of it is the history of mistrust between European countries, especially these two.
The Constitution was a first institutional step to try to solve this; but at the" core countries like France and the UK have to admit that they cannot go it alone anymore. Having a joint EU seat at the UN and other organisations would be the appropriate step to have a seachange in Europe's influence. In the long run, we're all dead. John Maynard Keynes