Israel's president, Shimon Peres, has warned the prime minister that a military attack on Iran’s nuclear facilities could provoke a broader conflict.

Peres is the first senior politician to advise Ehud Olmert against such an attack at a time of growing tension when other leading figures are threatening airstrikes unless Tehran halts its nuclear programme.

The Israeli air force has rehearsed an operation to destroy sites connected with the project.

“The military way will not solve the problem,” said Peres, the 85-year-old founder of the Jewish state’s nuclear programme, in an interview with The Sunday Times.

“Such an attack can trigger a bigger war.”

Sipping black coffee at the presidential residence in Jerusalem, Peres also criticised American foreign policy in highly unusual terms for an Israeli leader, saying it relied too much on military force in attempts to impose democracy on the Middle East.

“Bush stood up with the democratic slogan [for the Middle East] which is based on American democratic ideas and faced . . . enormous opposition,” he said.

“In my opinion, the Americans are making a mistake in their foreign policy.

“When they intervene abroad, they’d do better using the economy, which doesn’t provoke such antagonism.”

Peres explained: “If you suggest elections to the Saudis or to King Abdullah of Jordan they will refuse, as they regard democracy as a new religion and they want to remain Muslims. But if American businessmen offer high-tech companies, they would be most welcome.”

Turning to Tehran’s nuclear threat, he said: “There are two ways – a military and a civilian way. I don’t believe in the military option – any kind of military option,” he concluded, admitting with a smile that “what I’m saying to you I say to Olmert, but I can’t tell you what Olmert says to me”.

The views of the Israeli prime minister and defence minister are not secret, however. Both have vowed that Israel will not allow Iran to acquire nuclear weapons. They are convinced that Iran is developing a nuclear capacity for military reasons, not for peaceful purposes as President Mahmoud Ahmadinejad claims.

Peres, a believer in international cooperation, said: “We need a wider coalition to stop Ahmadinejad.”

He believes Iran is not the “enemy” of Israel and that such problems lie not in a country obtaining nuclear weapons, but in dangerous leaders like Ahmadinejad possessing them.

“I recently told [Vladimir] Putin [the Russian prime minister] that the Marxists say that religion is the opium of the masses. I say the religion is the opium of leaders [such as Ahmadinejad].”

Peres only just stopped short of suggesting that with different leadership Iran might be permitted nuclear weapons. “If Switzerland announces tomorrow that it has nuclear weapons, would anyone worry?

“If there were a wider international coalition, Iran would not be Israel’s particular problem.”

Peres believes that a serious effort to cut oil prices would help reduce Iran’s ambitions to a more realistic level. “The world has no choice – if nuclear weapons reach the hands of terrorists, it will be impossible to rule the world.”

Although as focused as ever, the president looked fragile and alone. He has enjoyed six decades of political life – he worked with Israel’s founder David Ben-Gurion and has had two spells as prime minister – but his wife Sonia refuses to join him in the presidential residence and he tells visiting friends that he’s living in “a golden cage”.

He thrives on international visits and his travel budget is bigger than that of any previous Israeli president. This weekend Peres is in Rome, probably trying to persuade European leaders to step up the pressure on Iran.

“An American general once said that you only go to war if you have no other option. We have another option,” he said.

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