WASHINGTON (AP) — Defense Secretary Robert Gates says it’s a mistake to set a deadline to end American military action, as some liberals have sought, and that a defeat would be disastrous for the U.S.In a stern warning to critics of a continued troop presence in Afghanistan, Gates said the Islamic extremist Taliban and al-Qaida would perceive an early pullout as a victory over the United States as similar to the Soviet Union’s humiliating withdrawal in 1989 after a 10-year war.”The notion of timelines and exit strategies and so on, frankly, I think would all be a strategic mistake. The reality is, failure in Afghanistan would be a huge setback for the United States,” Gates said in an interview broadcast Sunday on CNN’s “State of the Union.” Gates’ pointed remarks came as President Barack Obama re-examines his administration’s strategy in Afghanistan.——Contact the Daily Reveille’s news staff at [email protected]