King Features Syndicate distributed Hackworth's weekly column "Defending America". Many of his columns discussed the War on Terrorism and the Iraq War and were concerned with the policies of the American leadership in conducting the wars, as well as the conditions of the soldiers serving. Hackworth continued the column until his death from bladder cancer in May 2005. Associates believe that his cancer was caused by exposure to Agent Blue (a defoliant used in Vietnam), and are lobbying the United States government to have the substance labelled a known carcinogen like the more famous Agent Orange.