The diplomat, John Brady Kiesling, the political counselor at the United States Embassy in Athens, said in his resignation letter, "Our fervent pursuit of war with Iraq is driving us to squander the international legitimacy that has been America's most potent weapon of both offense and defense since the days of Woodrow Wilson."
Mr. Kiesling, 45, who has been a diplomat for about 20 years, said in a telephone interview tonight that he faxed the letter to Secretary of State Colin L, Powell on Monday after informing Thomas Miller, the ambassador in Athens, of his decision.
He said he had acted alone, but "I've been comforted by the expressions of support I've gotten afterward" from colleagues.
"No one has any illusions that the policy will be changed," he said. "Too much has been invested in the war."