WASHINGTON: Iran has hidden a large part of its atomic complex in networks of tunnels and bunkers across the country, shielding its infrastructure from military attack in warrens of dense rock while obscuring the scale of its nuclear effort, according to reports yesterday.

The effort to hide its capability complicated the West's military and geopolitical calculus and helped shield Tehran from attack, US reports said.

The Obama administration is pressing for strong and immediate new sanctions against Tehran over its nuclear program. Analysts told The New York Times that Iran's tunnelling - which Tehran calls a strategy of "passive defence" - was a crucial factor behind the push for non-military solutions to the issue.

The report said US Secretary of Defence Robert Gates had discounted the possibility of a military strike against Iran, in the belief it would only slow Tehran's nuclear program by one to three years while driving the project further underground.

Analysts told the paper that Israel, which has taken the hardest line against Iran, might be particularly hampered by the tunnels, given its less powerful military and intelligence abilities.

"It complicates your targeting," Richard L. Russell, a former CIA analyst now at the National Defence University, told the paper yesterday. "We're used to facilities being above ground. Underground, it becomes literally a black hole. You can't be sure what's taking place."

US government and private experts told the paper there were hundreds, perhaps thousands, of tunnels in Iran, and that the lines separating their use could be fuzzy. Companies owned by the Islamic Revolutionary Guards Corps of Iran, for example, built civilian as well as military tunnels.

No one in the West knows how much, or exactly what part of Iran's nuclear program lies hidden in the tunnels.

The report said the original hub of the nuclear complex at Isfahan consisted of scores of buildings that were easily observed and easy to attack, but US government analysts said that in recent years Iran had honeycombed the nearby mountains with tunnels. Satellite photos showed six entrances.

But the Obama administration has been careful to leave the military option on the table against Iran, and the Pentagon is racing to develop a deadly tunnel weapon. The report said the device - seven metres long and called the Massive Ordnance Penetrator - began as a 2004 recommendation from the US Defence Science Board, a high-level advisory group to the Pentagon.

It underwent preliminary testing in 2007, and its first deployment is expected in the northern summer. It will be carried by the B-2 stealth bomber.

The report yesterday came as a Pentagon-sponsored study by the Rand Corporation said the Revolutionary Guards had "gained primacy" in Iran since the 2009 presidential election.

The Massive Ordnance Penetrator (MOP) GBU-57A/B is a project by the U.S. Air Force to develop a massive, precision-guided, 30,000-pound (13,608 kg) "bunker buster" bomb.[1] This is substantially larger than the deepest penetrating bunker buster presently available, the 5,000-pound (2,268 kg) GBU-28.

Northrop Grumman announced a $2.5-million stealth-bomber refit contract on July 19, 2007. An undisclosed number of the U.S. Air Force's 20 B-2s will be able to carry two 15-metric-ton MOPs.

The initial explosive test of MOP took place on March 14, 2007 in a tunnel belonging to the Defense Threat Reduction Agency (DTRA) at the White Sands Missile Range, New Mexico. The exact location of the tunnel was not announced, but comparison of a photograph of the site with aerial photography suggests it was at the DTRA Capitol Peak Tunnel Complex in the vicinity of 33°26′24″N 106°27′18″W / 33.440°N 106.455°W / 33.440; -106.455.

On October 6, 2009, ABC News reported that the Pentagon had requested and obtained permission from the U.S. Congress to shift funding in order to accelerate the project.[6][7] It was later announced by the U.S. military that "[f]unding delays and enhancements to the planned test schedule "meant the bomb would not be deployable until December 2010, six months later than the original availability date.[8]

As the news of the first British casualty in Afghanistan in 2010 broke this week, fingers continued to point conclusively towards Tehran as being the financial and tactical backbone behind the insurgencies in Afghanistan and Iraq.

A Tehran-backed Taliban in 2009 inflicted the bloodiest year for British troops since the Falklands, killing 108 soldiers in Afghanistan. Now, as the town of Wootton Bassett prepares for the return of another fallen British hero, one must ask why Britain is appeasing an Iranian regime that is helping to inflict such heavy losses upon our young military personnel who are risking their lives in Afghanistan and Iraq.

Currently, while rumours persist of a prisoner swap to obtain the release of hostage Peter Moore, kidnapped more than two years ago in Iraq, the cost of a dubious policy of talking to terrorists is leading Iraq and Afghanistan further into the hands of Tehran's leadership. Unfortunately, the convenient timing of the release of Qais al-Khazali, a senior figure within the Righteous League, a militant group backed by Iran who kidnapped Moore, raises further questions regarding a prisoner swap deal.

Although the US military insists that Moore was held for part of his two and half years of captivity in Iran, the British Foreign Office and prime minister Gordon Brown continue to issue denials. So, what evidence have the US authorities seen which we have not? Or is the answer simply that the British government continues to deny the destructive role played by Tehran in Afghanistan and Iraq, because it believes that appeasing the mullahs' regime will bear fruit?

Continuing to take a blinkered view of the negative role played by Tehran in the vain hope that appeasement will bring about change is not only naive, but extremely dangerous. As we move into the next phase on the battlefield in Afghanistan, and Iraq builds up to elections later next month, Britain must adopt a much more distinctive policy towards a regime that is working hard to undermine the prospect of democracy and hamper the early withdrawal of British troops for its own political purposes.

Iran's support for the Taliban involves both financial and technical assistance, including the supply of IED roadside bombs and the training required for their use. Yet Tehran has been invited to a London conference later this month to help solve the ever growing problems in Afghanistan? You couldn't make it up. The major issue for discussion at this conference should be how to end Tehran's destructive influence. It doesn't wish to be a part of the answer but it will continue to be central to the problem and it is ludicrous to think that an invitation to a London conference will change that view. Appeasement didn't work in Berlin in the 1930s and it won't work in Tehran now. If our prime minister thinks that turning a blind eye will make the matter disappear he is deluding himself and letting the nation down.

Tehran is and will continue to be one of the biggest foreign policy issues facing the nation in 2010. If the British government seriously wishes to find a solution to the Iran problem, they need look no further than the streets of Tehran and the Iranian people's determination to purse democratic ambitions.

For a number of years now, colleagues and I on the British Parliamentary Committee for Iran Freedom have worked with Iran's largest opposition group in exile, the National Council of Resistance of Iran, and its president-elect Maryam Rajavi to strengthen our policy towards Iran whilst seeking increased support for the Iranian opposition movement.

A new direction in our relations with Iran must include the imposition of a wider range of targeted sanctions that are forcibly monitored. Second, we have to change our attitude to the Iranian democratic opposition in exile and work more closely with them. We should recognise their wide-ranging connections within the democratic movement inside Iran, which has surprised the world and has sizably increased the possibility of internal regime change.

Finally, we should start sending a firm but consistent message to the mullahs' regime that we mean what we say and we should cease our policy of appeasement which has been so harmful to our national interest.

Continuing a policy of appeasement will have only one outcome, that of forcing both Afghanistan and Iraq even further towards Tehran's sphere of influence. Strong and consolidated action now will not only reduce British troop losses but will hasten their return. And that really is in Britain's interest.