While this might have been a necessary evil during the Cold War, given that any direct confrontation between the super powers could have turned nuclear very quickly, it is far less defensible today. The consequences of this need for unanimity have been all too apparent this week as the Russians and Chinese have moved to guarantee that the Burmese junta can deal with the protestors any way they want. (Any way they want has already involved the death of nine people)
To make things worse, the UN is a convenient get out--and here I agree with Tim Montgomerie--for any Western politician who wants to appear as if they are doing something. So on Darfur, politician after politician announced something must be done, genocide must never happen again and then concluded by saying that’s why we must go the UN. They did this despite the fact that it was obvious that the UN route would not work because of the Chinese veto. The result: three years of inaction thanks to entirely predictable Chinese blocking tactics. (Even now it remains to be seen if the UN resolution that has been secured is sufficiently robust.)
Next time someone starts lecturing you about how only wars signed off on by the UN are moral, you might want to remind them that by this logic any legitimate war has to be signed off on by a Communist dictatorship and a ‘managed democracy.’ That’s a pretty odd form of morality.