This week Iran celebrates the 29th anniversary of the Islamic Revolution, the popular wave that swept today's Shiite Muslim theocracy into power. It is Iran's equivalent of the U.S. Fourth of July, marking the day that the Shah's army gave up and the Ayatollah Ruhollah Khomeini took control of the country in 1979.
President Mahmoud Ahmedinejad drummed up national pride at a thousands-strong rally in Tehran's Azadi Square Monday, defiant in the face of diplomatic isolation and possible new economic sanctions on his country for its controversial nuclear materials.
"Our nation doesn't back off even one bit from its nuclear rights. … From our standpoint, the nuclear issue is over," Ahmedinejad told the crowd as members of the Revolutionary Guard stood by. He spoke for roughly an hour on everything from theology to the country's scientific and cultural achievements.
For men, women and children in the crowd chants of "death to America" mixed the anti-Western fervor of the revolution with the ideological tension between the United States and Iran.
"[The revolution] was an explosion of light … the Iranian people became victorious over the Shah's regime," said 13-year-old Sepehr Norouzi, who attended the rally with his school. He called the United States "a bully that only sees its selfish interests."
Mehrdad Ashadi, 14, had a different take. "America is a great country in science and technology. … I would love to go there someday."
The holiday known as 22 Bahman -- the Persian calendar's equivalent of Feb. 11 -- marks a day still fresh in the minds of those who lived through the transition from the Shah's regime to the Islamic Republic. One of them, Ebrahim Yazdi, lived it at its epicenter, flying with the Ayatollah Khomeini on his return from exile in France and serving as Iran's first foreign minister in the new regime.
What Yazdi remembers of the day was the euphoria of success after revolutionaries deposed the Shah Mohammed Reza Pahlavi, whom they accused of serving the West and torturing critics of his regime.
"There was ecstasy. There was a hope for the future. Pride for their past, that they had succeeded," he remembered.
Yazdi, a critic of some policies of today's Iranian regime, said that day in 1979 also came with a sense of vulnerability -- an open question of where the revolution would lead.
"Down deep I was concerned," he told ABC News. "It was a new birth -- everybody's happy. But we know this baby, [the revolution], grows. … As it grows up there are a lot of problems. Therefore it was joy, happiness, pride, but at the same time concern."
The tone of the revolution, in contrast to the pro-American Shah, was a vocal hostility to the United States. It culminated months later in November 1979 with the seizing of the American Embassy -- the start of the hostage crisis.
"In the eyes of many Iranians the Americans and the British were part of the Shah's crimes," said Yazdi.
As the revolution is remembered, Tehran shows signs of that hostility, from "Down with the USA" signs at the Azadi Square rally to painted murals around the city condemning America and Israel.
"Many governments need enemies to blame them for their shortcomings," Yazdi offered as his explanation. "This is a psychological projection that happens not only in a country like Iran but [also] in America."
Still, he says, the hostility is not necessary or desired by all in today's Iran. "Iranians love American people. Down deep there is a sympathy. Many Iranians … have been there. They studied there, they know the American way of life."
The revolutionary aggression on signs, chants and murals, he said, are misinterpreted. "The American people should recognize that when they say 'Death to America' they do not hate American people .They want to express their views on American deeds -- foreign policies."
Next year the Islamic Revolution marks its 30th anniversary. By then there will be a new president in the White House to direct the foreign policy and direction of the U.S.-Iranian relationship.