On big issues like war in Iraq, but in many other issues they simply must be multilateral. There's no other way around. You have the instances like the global warming convention, the Kyoto protocol, when the U.S. went its own way.
Hans BlixThe South Africans decided that they would like to prove to the world they did not have any nuclear weapons and their decision was not doubted because it was the end of the Cold War, it was also the end of apartheid.
Hans Blix