Iranians flooded the streets of the capital today by the hundreds of thousands.
Even amid a crumbling economy and deep internal divisions, the 1979 Islamic revolution remains a unifying force here and today was no different.
"We're very happy," one marcher said of events in Tehran marking the 30th anniversary of Iran's transformation from a constitutional monarchy to an Islamic republic. "Just look at the size of the crowd."
Many of the events were directed at America, with marchers chanting, "Down with the USA!"
Others carried effigies of U.S. and Israeli leaders. Many said they see the revolution as the time when Iran finally broke free from dependence on the United States, which remains a powerful sentiment.
When asked if Iranian leaders should accept President Obama's offer to talk, an offer he repeated during his news conference Monday night, many Iranians said the burden of change is on the United States.
"It depends on the conditions," one man said. "It depends on keeping the dignity and respect of these people and revolution in Iran."
"They need to respect us at the same level that they are, as equals."
Iranian President Mahmoud Ahmadinejad today echoed the call for respect, telling the crowd, "The Iranian nation is ready to hold talks, but talks in a fair atmosphere with mutual respect."
Khazem Jalali, spokesman for the Iranian parliament's National Security Committee and among those in the crowd, said, "For 30 years, the U.S. has applied an array of policies against us. What's important isn't the change in tone, but a change in action."
For Iran, that means assurances that the United States will not seek regime change and will loosen economic sanctions. What is not on the table, many say, is Iran's nuclear program.
"I don't think that the Iranians will be willing to give up uranium enrichment because the whole revolution was about independence and to be dictated to by the Americans is completely unacceptable to Iran," said Majid Marandi, head of North American studies at the University of Tehran.
"The Iranians are quite willing to give assurance that the program will remain peaceful."
Other areas of potential cooperation include improving stability in Iraq and Afghanistan, Iran's neighbors to the south and east. But for Iranians, any cooperation should come from a position of strength.
"America has so many problems," Marandi said. "I think any help from Iran would be of terrific help to the U.S."
Some people in Iran question the government's hard-line stance against the United States. In the religious city of Qom, Ayatollah Mousavi Tabrizi, once a close ally of the late revolution leader Ayatollah Khomeini, is critical of some Iranian leaders.
"Some in government are ruling as if we're at war," he said. "They blame their own flaws and shortcomings on foreign enemies to impose themselves on the people."
But that is a minority voice here. What is more evident today is an Iran full of new confidence to stand up to America.