Lord Bingham of Cornhill, who has just stepped down as senior law lord, cited the US-led invasion of Iraq, its "redefinition" of torture and the detention conditions of suspects in Guantanamo Bay.
"Particularly disturbing to proponents of the rule of law is the cynical lack of concern for international legality among some top officials in the Bush administration," he said in a lecture to mark the 50th anniversary of the British Institute of International and Comparative Law.
It was not clear, he added, what, if any, legal justification the US Government relied on for its invasion of Iraq, although prominent figures had made clear their ambition to remove Saddam Hussein.
He was also scathing about the legal advice of the former Attorney-General, Lord Goldsmith, on Britain's invasion of Iraq which was "flawed" in stating that a second UN Security Council resolution was not needed.
If that was right, the invasion was a "serious violation of international law and of the rule of law," he said.
