Cryto, I agree with that the UN has is a useless entity but not only in this regard but also whenever US feels that it has the right to veto the resolutions that are passsed against Israel and there are plenty of resolutions that they have trampled all over in the past.One can not be selective about these resolutions.
It isn't just the US. Nations everywhere defy UN resolutions whenever they please. The reason the UN is useless is because it is too inclusive. Instead of becoming a body of nations working to solve world problems, it has become an official gathering place for any and every thug, dictator, and psychopath to use as a podium.
The UN is a good idea - just poorly executed. There are too many different opinions represented to get anything accomplished. I know that sounds anti-democratic, and I don't mean to suggest that everyone should be made to agree. However, the UN is no longer able to present a united front, and that makes it useless and irrelevant.
So, to turn back into the topic, I think France understands the importance of a united front when trying to achieve a specific objective. The rhetoric used by France now is more harsh because the French do not want to appear as being at odds with the US on the Iranian nuclear issue.
United fronts are very important - especially when faced with global issues like nuclear proliferation, genocide, and human rights.