NATO, guided by Washington, went far outside the UN resolution declaring a no-fly zone over Libya. NATO in blatant violation of the UN resolution provided the air attack on the Libyan government that enabled the CIA-supported "rebels" to overthrow Gadhafi, killing many Libyan civilians in the process.
Under the Nuremberg standard (principle VI.a.i), it is a war crime to launch a war of aggression, which is what Washington and its NATO puppets launched against Libya, but, no sweat, Washington brought Libya freedom and democracy.
Assassinating foreign opponents is the West's preferred diplomacy. The British were at ease with it, and Washington picked up the practice. In his book, The Decline and Fall of the British Empire, Cambridge University historian Piers Brendon, the Keeper of the Churchill Archives, reports from the documents he has at hand, that in the build up to the "Suez Crisis" in 1956, British Prime Minister Anthony Eden told Foreign Office minister Anthony Nutting, "I want him [Nasser, Egypt's leader] murdered."
Brendon goes on to report: "Doubtless at the Prime Minister's behest, the Secret Intelligence Service did hatch plots to assassinate Nasser and to topple his government. Its agents, who proposed to pour nerve gas into Nasser's office through the ventilation system, were by no means discreet." The secret agents talked too much, and the scheme never came to fruition.
Last week in Malaysia a war crimes tribunal found George W. Bush, Dick Cheney, Donald Rumsfeld and their legal advisers, Alberto Gonzales, David Addington, William Haynes II, Jay Bybee, and John Choon Yoo guilty of war crimes. (ref)
But don't expect Washington to take any notice. The war crimes convictions are merely a "political statement."