JERUSALEM (Reuters) - Somewhere between sanctions and air strikes lurks a third option for those who seek to stop Iran's atomic program in its tracks: sabotage.
Politically deniable -- unlike failed diplomacy -- and much subtler than region-rattling military offensives, covert action of the kind used elsewhere by Israel and the United States could already be under way against the Islamic republic, experts say.
'Iran has been trying to go nuclear since the 1970s and has not yet managed,' said Gad Shimron, a veteran of Israel's Mossad spy service who now writes on defense issues.
'Who's to say there has not been sabotage already, now proving its worth?'
Britain's Daily Telegraph newspaper in August quoted Bush administration officials as saying sabotage tactics were being considered for Tehran. The Jewish state has said 'all options' are valid for preventing its arch-foe getting the bomb.
The United States and Israel accuse Iran of concealing a plan to build a bomb, but Tehran says its nuclear program is dedicated solely to meeting electricity demand.
Independent experts question, however, whether any disruption of Iran's supply lines through sabotage or menacing of its nuclear scientists would have a lasting effect on a network that has resisted scrutiny from the U.N. International Atomic Energy Agency (IAEA).
'Historically, sabotage has served to delay programs but has not been successful in terminating them,' said Gary Samore, a former White House adviser on non-proliferation now with the International Institute for Strategic Studies in London.
He cited a Norwegian heavy water plant struck by saboteurs between 1942 and 1944 to stop the Nazis getting the bomb -- a quest finally laid to rest by Germany's defeat in World War II.
'Delay is good if, in the meantime, something conclusive happens -- either a change of regime or a successful war.'
Some Middle East security experts say even delays have key strategic value in a region notorious for its instability.