Here's the lesson of the past three years: The UN kills.
In 2003, you'll recall, the US was reviled as a unilateralist cowboy because it and its coalition of the poodles waged an illegal war unauthorised by the UN against a sovereign state run by a thug regime that was no threat to anyone apart from selected ethnocultural groups within its borders, which it killed in large numbers (Kurds and Shia).
Well, Washington learned its lesson. Faced with another thug regime (Sudan) that's no threat to anyone apart from selected ethnocultural groups within its borders which it kills in large numbers (African Muslims and southern Christians), the unilateralist cowboy decided to go by the book. No unlawful actions here. Instead, meetings at the UN. Consultations with allies. Possible referral to the Security Council.
And as I wrote on this page in July 2004: "The problem is, by the time you've gone through the UN, everyone's dead." And as I wrote in Britain's Daily Telegraph in September 2004: "The US agreed to go the UN route and it looks like they'll have a really strongish compromise resolution ready to go about a week after the last villager's been murdered and his wife gang-raped."