Tehran, Iran ? Iran’s leadership boasts it is safe from U.S. military action, saying Washington knows an attack would find no world support and send oil prices skyrocketing. That confidence is buoying the government in its standoff with the West, despite new sanctions.

Iran’s top nuclear negotiator, Saeed Jalili, on Friday dismissed the U.S. announcement a day earlier of new sanctions, saying “Washington will isolate itself” with the measures.

“They have imposed sanctions on us for 28 years. The new sanctions are just in the same direction,” Jalili said as he returned from talks with European officials in Germany and Italy, according to the state news agency IRNA.

President Mahmoud Ahmadinejad is taking a hard line in the confrontation with the West over its nuclear program, apparently confident Washington’s main pressure tools – sanctions and the threat of military action – are ineffective.

It could be a risky bet. Ahmadinejad’s main vulnerability is domestic: rising criticism from a public angry over the country’s poor economy and from politicians disillusioned by what they call his mismanagement. Even some conservatives have expressed fears Ahmadinejad is pushing Iran into future trouble over the nuclear issue.

Further sanctions, even unilateral ones from the U.S., could hurt the economy more by further isolating it from international finance – and Iranians were already expressing worries over the new measures.

Ahmadinejad, who faces elections in 2009, knows “jobless and poor people will not vote for him if his policies bring them more difficulties,” said Ahmad Bakhshayesh, a political science professor at Tehran’s Azad University.

But he believes “unilateral economic sanctions by Washington are not strong enough (to hurt Iran) due to Iran’s widespread economic relations with the world.”

Suzanne Maloney, an expert on Iran at the Washington-based Brookings Institution, said that while sanctions have put pressure on the regime, oil prices have dampened their effect.

“Yes, life becomes more expensive, but right now they have a fairly considerable cushion,” she said, adding that sanctions might force the government to become more fiscally responsible.

“A flush Iran has been an irresponsible Iran. Most of their economic problems have been caused by having too much cash on their hands,” she said. In the face of new sanctions, “it’s not unthinkable that they’ll take more responsible measures at home that will cut some of the internal pressure.”

Recent U.S. statements have deepened Iranians’ fears of attack. Last week, President Bush warned that a nuclear Iran could lead to “World War III,” and Vice President Dick Cheney vowed Sunday that the U.S. and other nations will not allow Iran to obtain a nuclear weapon. Iran denies it is seeking nuclear weapons, saying its program aims only to produce electricity.

After the U.S. sanctions announcement, a string of Iranian military officials came forward to insist America will not attack Iran, citing strain on the U.S. military from the Iraq war and worries over high oil prices.