TEL AVIV: Somewhere between sanctions and air strikes lurks a third option for those who seek to stop Iran's atomic programme 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 defence 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 kosher 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 programme 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 UN International Atomic Energy Agency (IAEA).
"Historically, sabotage has served to delay programmes 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 Two.
"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.
COVERT CAMPAIGN: The precedent usually cited for a military strike on Iranian atomic sites is Israel's 1981 bombing of the Iraqi reactor at Osiraq. That move drove Saddam Hussein's nuclear programme underground until it was uncovered by the IAEA in 1991.
Well before Osiraq, a quieter campaign was in full swing. Nuclear components destined for Baghdad were blown up in a French port. An Egyptian nuclear physicist hired by Iraq was killed in his Paris hotel. Bombs exploded near an Italian firm supplying Saddam Hussein with laboratories for atomic testing.
Saddam blamed the United States and Israel for the sabotage spree. Neither country commented, but then Israeli Prime Minister Menachem Begin told an American interviewer he hoped France and Italy had "learned their lesson" for helping Iraq.
Tehran fears it could be next in line after US-led forces toppled Saddam last year. "The Iranians are very clear about what happened to the Iraqi nuclear programme and would have learned their lessons," said Alex Vatanka, an analyst with Jane's Sentinel Security Assessments. "In terms of supply lines and technology, they are extremely unlikely to use limited sources."
Among Iran's nuclear suppliers have been North Korea, Pakistan and China, all hard for Western diplomats to monitor. Under its 1993 Counter-proliferation Initiative, Washington claimed the right to act covertly against illicit weapons of mass destruction (WMD) programmes. But a later US-led treaty, the Proliferation Security Initiative, includes Russia, which also openly provides Iran with nuclear know-how.
A QUESTION OF JURISDICTION: While no one accuses countries friendly to the United States of knowingly arming Iran, private citizens may not feel such constraint, a fact that could complicate sabotage attempts.
"The understanding in the intelligence world is that those individuals who help rogue regimes knowingly put themselves at risk of reprisal," said Shimron. "An agency that wants to operate in a friendly country has to weigh the possible fallout, but usually there is enough coordination between governments to ensure that it all goes smoothly as long as no one is needlessly hurt."
Vatanka said several Iranians who acquired scientific training in the West had answered a call by Tehran to return and work on their homeland's atomic programme. A German man is also under investigation for what national media charged was an attempt to supply Iran with components for nuclear weapons.
"If the Israelis believe sabotage is the only way of stopping Iran getting the bomb, I think they will go with it, even if this ends up harming relations with Europe," Vatanka said. "The Europeans have invested enormous diplomacy in Iran, but that means little to those planning Israel's self-defence."
A new report by the Dubai think tank Gulf Research Centre says Tehran could retaliate for any sabotage on its atomic plans by ordering proxies to attack US targets in the Gulf or stepping up support for Palestinian militants fighting Israel.
There are also risks if the secrecy around sabotage lapses. In 1963, Swiss police nabbed an Israeli suspected of threatening the daughter of a German scientist linked with Egypt's missile programme.
The ensuing trial clouded Israel's relations with West Germany and Switzerland and prompted the Mossad chief's resignation, although many historians believe it also served as a venue for publicising Egypt's military plans. -Reuters