When Secretary of State Condoleezza Rice visits Europe later this week, the issue of Iran's nuclear program is likely to be high on her agenda. Diplomats on both sides of the Atlantic say Iran is one of their most serious challenges, and they have been struggling to develop a joint strategy on how to deal with it. VOA's Michael Drudge has more from London.

At her confirmation hearings last month, Secretary of State Rice said she is pessimistic about the prospects of improved relations with the Iranian government.

"This is just a regime that has a really very different view of the Middle East and where the world is going than we do. It really is hard to find common ground with a government that thinks Israel should be extinguished. It is difficult to find common ground with a government that is supporting Hezballah and terrorist organizations that are determined to undermine the Middle East peace that we seek."

There is growing concern in the United States and Europe about Iran, and particularly the Iranian nuclear program.

Iranian officials say they intend to use nuclear power only to generate electricity, not to build a bomb.

But many experts on the region say Iran cannot be trusted. One of them, Reuel Marc Gerecht, is a former CIA Middle East analyst now with the American Enterprise Institute, a Washington policy studies group.

"The track record of the Iranians over the last 20 years of this program is quite clear. Its clandestine nature, its repeated deception, clearly indicates that they are after the capacity to produce a nuclear weapons program, and certainly if one spends any time with British, French or German intelligence officers, they are of the same mind as American officials on this issue."

Mr. Gerecht is among those who say a military strike against Iran may be necessary if diplomacy fails.

Such talk has unsettled officials in Britain, France and Germany, whose diplomats have negotiated a temporary freeze of Iran's program to produced enriched uranium, the kind needed for a nuclear bomb.

Following recent media reports that American special forces were in Iran picking out potential military targets, British Prime Minister Tony Blair told a questioner in parliament that he knows of no contemplation by the United States to attack Iranian nuclear facilities. But he also stressed that Iran is a big problem.

"There is indeed a serious issue as to Iran and nuclear weapons and its obedience to the atomic energy authority. And what we are doing in Europe, in concert with America and others, is trying to make sure that Iran comes into compliance with its international obligations."

Some analysts say the United States cannot consider any military action against Iran with so many American troops still deployed in neighboring Iraq.

Mick Cox is a professor of international politics at the London School of Economics who discussed the issue recently on British television.

"The reality is, however, that so bogged down in Iraq, contemplating any further military action, serious military action in the Middle East generally or towards Iran particularly, is ruled out. Everybody realizes, frankly, that a real war against Iran would be a political, if not also a military disaster. Therefore, the United States has to look for other options. But what are they? And they have not got an answer."

Nor, he says, does anyone else.

There are experts who say Iran is still a long way from being capable of producing large-scale quantities of weapons-grade uranium.

Among them is Gary Samore, a senior fellow at London's International Institute for Strategic Studies and a former special assistant on non-proliferation issues for then-President Bill Clinton.

Mr. Samore says Iran would need one-thousand centrifuges working for two years to produce enough weapons-grade uranium to build one nuclear weapon. He says right now the Iranians have about 164 such machines.

But Mr. Samore says there is no reason to be reassured by Iran's promises that it will use nuclear technology only for peaceful purposes.

"From a technical standpoint, the debate about whether Iran's nuclear program is peaceful or military is really meaningless. Because fuel-cycle facilities like the enrichment plant can be used for both civilian and military purposes. What matters is the issue of political intention, not technical capability."

Mr. Samore also says media speculation about possible military action against Iran is, as he puts it, "overheated."

"Serious consideration of a military option is very premature because the key facilities are still many years away from completion and of course the diplomatic track is still alive for the time being."

But there are signs of a diplomatic stalemate between Iran and the European negotiators from Britain, France and Germany following talks last month.

The Europeans say they are insisting that Iran permanently cease and dismantle its capability to enrich uranium, while Tehran says it will only agree to more international inspections and some limitations on the program.

Europe is offering Iran political and economic incentives if it gives up uranium enrichment, and Russia is prepared to provide fuel for Iran's nuclear power plant.

Officials on both sides of the Atlantic say Iran could be referred to the U.N. Security Council for possible sanctions if the negotiations fail. But if the Europeans and Iranians achieve a breakthrough, Washington might be called upon to set aside its deep suspicions of Iran and provide some incentives and security guarantees to make a deal work.