Iran's opposition movement brought its struggle back to the streets of Tehran on Wednesday, turning the 30th anniversary of the U.S. embassy takeover — typically marked by government-sanctioned displays of anti-Americanism — into a protest against the government. Defying police orders to disperse, hundreds of people gathered at a square not far from the old U.S. embassy, while thousands of other protesters gathered in impromptu crowds on street corners around the city, dodging riot police and plainclothes government security officers.The displays of defiance do not appear to be nearly as large as the massive demonstrations that were staged in June to protest the disputed re-election of President Mahmoud Ahmadinejad. Nor are they enough to pose a direct challenge to the government, which has overwhelming control over the streets and national security. But they are having an effect far beyond the skirmishes in Tehran, pushing the Iranian government into a harder and harder line against its internal foes and into confrontation with the West.Indeed, while opposition protesters played cat-and-mouse with police, the government bused in supporters by the thousands for anti-American protests in front of the old embassy, now known as the "Den of Spies." They chanted the traditional "Death to America" and "Death to Israel" slogans. The government blamed the U.S. and European governments for fabricating the post-election unrest in an attempt to stage a coup d'état. Now the Iranian government is finding it more and more tempting to press the hot button of conflict with the West.There had been some hope among Iran watchers and the U.S. government that, in the aftermath of Ahmadinejad's disputed election, the Iranian government would have more incentive to accept President Barack Obama's offer for an open discussion about the fractured relations between Iran and the U.S. According to this line of thinking, a contested government in Iran would need a deal with the West to bolster its international legitimacy. Further to the argument, the conservative Ahmadinejad was said to be one of the few Iranian leaders who could then pull off an about-face on 30 years of anti-Americanism and do a deal with the "Great Satan."In fact, the opposite is turning out to be the case. That was evident in the rapid collapse last week of a U.N.-brokered nuclear deal that would have allowed Iran to continue enriching uranium while most of its stockpile would be shipped to Russia for conversion into reactor fuel. The government initially seemed to welcome the deal, but then it quicly retreated last week amid a chorus of criticism inside Iran. Hard-liners reacted with knee-jerk suspicion that the U.S. was secretly trying to steal Iran's uranium, and moderates smelled an opportunity to attack the government. Finally, on Tuesday, Supreme Leader Ayatullah Ali Khamenei blamed U.S. arrogance for the failure of the talks and made comments that seemed to dash any hopes of a deal with the U.S. "The Islamic Republic of Iran decided from the beginning not to prejudge and instead to consider the slogan of 'change,' " he said, apparently referring to the Obama Administration. "But what we have witnessed in practice during this period of time has been in contradiction with the remarks that have been made."As the opposition movement continues, the hard-liners who took control in the aftermath of the election are closing ranks to an ever greater degree. In the weeks before the current demonstrations, the government sent a warning that it was preparing to go after the top leaders of the opposition by opening an investigation into the activities of Mehdi Karroubi, one of the losing presidential candidates. Karroubi has been collecting evidence of abuse and murder by government security services in the aftermath of the election. The fact that the government could turn against someone with such impeccable revolutionary credentials (Karroubi was a confidant of the late Ayatullah Ruhollah Khomeini and a former speaker of parliament) is a sign of just how tightly the new circle of power is drawn. If anyone needed a reminder of how little room is left for legal political opposition, last week Khamenei called it a crime to question the results of the election.