The timing of President Barack Obama's announcement of Iran's newest uranium enrichment plant came as supporters of opposition leader Mir-Hossein Mousavi have been seeking new momentum in protests against the disputed June re-election of Ahmadinejad. Massive street rallies over allegations of voter fraud have shaken the regime, but security forces led by the Revolutionary Guard have backed Ahmadinejad and supreme leader Ayatollah Ali Khamenei. Mousavi's Green Movement blames Ahmadinejad for recklessly inciting the West and raising the prospect of new economic sanctions by his stubbornness and cat-and-mouse games with international nuclear inspectors. As Ahmadinejad headed for the United Nations last week, the opposition announced its suspicions -- shared by the U.S. and denied by Iran -- that the regime is refining technology to produce atomic weapons. 'The Iranian Green Movement does not want a nuclear bomb, but instead desires peace for the world and democracy for Iran,' read a statement addressed to the world by one of the movement's spokesman, filmmaker Mohsen Makhmalbaf, who lives in Paris. 'The Green Movement in Iran furthermore understands the world's concerns and in fact has similar concerns itself.' Mousavi and other top opposition figures, fearing they could face arrest over accusations of aiding the enemy, have not commented directly on the latest charges from the U.S. They support nuclear enrichment for civilian energy use but have criticized government management of the program. An opposition activist in Tehran, who gave his name only as Taqi H for fear of being arrested, concurred, 'I think the revelation of a second nuclear site will lead to more pressure on Ahmadinejad's government. This is good for the Green wave in Iran and the rift will increase for sure if pressure builds up.' Khamenei and Ahmadinejad historically have been able to rally the Islamic Republic around its nuclear ambitions, which they say are for civilian purposes only, during periods of high inflation, unemployment and other domestic failings. One of the hard-liners' most potent caricatures has been painting reformers and opposition members as stooges and agents of the West who betray the principles of the 1979 Islamic Revolution. But in an era of political turmoil that has seen the largest anti-government demonstrations since the revolution, it is unclear whether the nuclear gambit would work again. At the same time, the opposition faces its own dangers: more arrests and crackdowns if it is perceived as appeasing the West. 'I guess we will be shocked in future by further (nuclear) revelations,' said Reza Hasani, a Tehran bookseller. 'The rift inside the country between the two camps will widen. At the same time, any opposition member inside the country that sides with the international community will be easily labeled as pro-West or pro-foe. ... Pressure on the dissidents Green or whatever will increase.' Indeed, many Iranians resist compromising on a nuclear agenda that was enshrined in the national psyche even before the revolution swept the shah from power. Heshmatollah Falahatpisheh, member of the Iranian Parliament's Foreign Policy and National Security Committee, said his country would not abandon its endeavors, no matter what the consequences. 'Many countries like Iraq saw their nuclear facilities bombed by Israel in 1981, but Iranians have diversified and scattered their nuclear facilities,' Falahatpisheh was quoted by the official news agency IRNA as saying. 'The Western governments have to recognize the reality of nuclear Iran and back down. ... Iran has never stepped back in the face of threats and it always manages to force the Western governments to recognize its nuclearization.' Mohammad Mohammadi-Golpayegani, who heads Khamenei's office, spoke with similar combativeness when he was quoted by the semiofficial Fars News Agency as saying, 'This new plant, God willing, will soon become operational and will make the enemies blind.' But Ahmadinejad's performance at the U.N. and in news conferences showed a defiant leader on the defensive, even as he brushed aside rebuke over Iran's long-undisclosed uranium enrichment plant. Pressure on the president tightened when Russia, one of Iran's allies on the U.N. Security Council, said it would reconsider imposing new economic sanctions. 'I believe the Iranians, if they feel they're really under the gun, will act differently,' said Ephraim Halevy, former head of Israel's foreign intelligence service. 'What will happen if there's a change of events and the pressure in Tehran will reach a high pitch -- whether it's a result of new sanctions or an outbreak of new tensions in the body politic and strains inside the leadership that are becoming ever stronger and more prominent? Suddenly public sentiment has begun to veer in a different direction.' The challenge facing Ahmadinejad and Khamenei is how to navigate international scrutiny leading to a meeting scheduled for Thursday between Iran and world powers. Iranian officials may end up granting the West wider access to its nuclear facilities, which could ward off new international sanctions. Yet in doing so, they could anger their backers if they give the impression that the regime is buckling to outside demands. On Saturday, Ali Akbar Salehi, director of Iran's nuclear program, showed signs of relenting by saying that U.N. inspectors would be allowed to visit the new plant, which is expected to house 3,000 centrifuges for enriching uranium. 'The West does not heed what we say about what our motivation or true intent is,' said Mehdi Motaharnia, a political scientist sympathetic to the Ahmadinejad camp. 'We cannot convince the Western elites. ... We are innocent on the nuclear issue and therefore the U.S and our opposition in Western governments have the upper hand in persuading the international community.' Staff writer Fleishman reported from Cairo and special correspondent Mostaghim from Tehran. Staff writer Richard Boudreaux in Jerusalem contributed to this report. 