CANBERRA — On March 17, Security Council Resolution 1973 authorized the use of "all necessary measures," short of an invasion and occupation, "to protect civilians and civilian-populated areas": the first United Nations-sanctioned combat operations since the 1991 Persian Gulf War.

Resolution 1973 was passed by a 10-0 vote within 24 hours of being introduced, contrary to prevailing expectations that the world once again would watch fecklessly from the sidelines.

In Bosnia, it took NATO over a year to intervene in 1999 with air power. In Libya, it took just one month to mobilize a broad coalition, secure a U.N. mandate to protect civilians, establish and enforce no-fly and no-drive zones, stop Moammar Gadhafi's advancing army, and prevent a massacre in Benghazi.