A military strike on Iranian atomic facilities would delay but not destroy the development of any nuclear weapons programme, diplomats and analysts said.
"Military action is not the answer," said a senior international diplomat involved in the investigation of Iran's nuclear plans. "It would only push them underground, like in Iraq."
Israel has hinted it could use airstrikes to destroy Iran's nuclear facilities, which it and Washington believe are part of an attempt to acquire atomic weapons under cover of a civilian nuclear power programme.
But Iran denies the chargem, and Iranian Defence Minister Mr Ali Skhamkhani said his country would respond to a military attack "with everything in our power".
Convinced that Saddam Hussein was developing nuclear weapons, Israel bombed Iraq's Osiraq nuclear reactor in 1981. But instead of stopping his quest for a bomb, Saddam went underground and worked in secret until the programme was uncovered by the UN nuclear watchdog in 1991.
Several analysts and diplomats said Iran had learned from Iraq's mistakes and might be hiding nuclear sites from UN inspectors, who have been investigating Tehran's atomic programme for nearly two years to verify that it is peaceful as Iran insists.
"I think it's impossible to take out Iran's nuclear weapons programme with military strikes," a defence industry expert said. "They can recuperate."
But Mr Gary Samore, director of studies at the International Institute of Strategic Studies in London, said military action could significantly delay any Iranian atomic-weapons programme.