U.N. Security Council Resolution 1973 (.pdf) resulted in prompt international action that delivered Libyans from the murderous violence Moammar Gadhafi had already inflicted on civilians early in March, as well as from violence he continued to threaten against what he called, in an eerie echo of Rwanda's murderous regime in 1994, the "cockroaches" who opposed him. Earlier, the council's Resolution 1970 (.pdf) had unanimously approved an arms embargo, asset freeze, travel ban and reference to the International Criminal Court. In addition, the U.N. Human Rights Council unequivocally condemned Libya, which led to the General Assembly's unprecedented decision to suspend Libyan membership in the council.
Behind these decisions, which were rapid and robust by U.N. or any standards, was the emerging norm of "the responsibility to protect" (R2P), the title of a 2001 report from the International Commission on Intervention and State Sovereignty (ICISS). Four years after its release, at the 2005 World Summit marking the U.N.'s 60th anniversary, although some 150 assembled presidents, prime ministers and princes agreed on little else, they did agree with the report's major conclusion: that military intervention to protect the vulnerable was desirable and acceptable -- not for garden variety human rights abuses but for "genocide, war crimes, ethnic cleansing and crimes against humanity."
With the exception of Raphael Lemkin's efforts that resulted in the 1948 Genocide Convention, no idea has moved faster than R2P in the international normative arena. "A blink of the eye in the history of ideas," concluded Gareth Evans, ICISS co-chair, former Australian foreign minister and past president of the International Crisis Group.