In a resignation letter to Secretary of State Colin Powell, Brown said he agreed with J Brady Kiesling, a diplomat at the US embassy in Athens who left in February because of President Bush's determination to order an attack on Iraq. 'I am joining my colleague John Brady Kiesling in submitting my resignation from the Foreign Service - effective immediately - because I cannot in good conscience support President Bush's war plans against Iraq,' he said. 'Throughout the globe the United States is becoming associated with the unjustified use of force -The president's disregard for views in other nations, borne out by his neglect of public diplomacy, is giving birth to an anti- American century.' Brown had served at US embassies in London, Prague, Krakow, Kiev, Belgrade and Moscow. He was most recently diplomat-in-residence at Washington's Georgetown University.