Close to a million people were killed in Rwanda in 1994 when the dominant Hutus turned against the Tutsis. The slaughter that went unchecked should have ensured that at the first signs of genocide the United Nations would act to prevent yet another human tragedy.

Not so. Genocide has been proceeding in the Darfur region of Sudan as if there had never been a commitment by the international community to make the vow “Never Again,” after the Jewish Holocaust, mean something. To date, the United Nations has shrunk from its responsibility to intervene and the United States, overstretched in Afghanistan and Iraq, is in no position to act unilaterally.