TEHRAN - Many of the Iranian students who led the storming of the US embassy in Tehran 30 years ago, and took more than 50 US diplomats hostage said they acted in response to Washington's refusal to hand over deposed shah Mohammad Reza Pahlavi.
They feared a repetition of US interference such as the CIA-organised coup in 1953 that overthrew nationalist prime minister Mohammad Mossadegh.
Chants of "Death to America" reverberated through the streets of Tehran as Iranian masses sang the praises of the daring move against the embassy.
Ayatollah Ruhollah Khomeini, founder of the republic, dubbed the building's capture a "second revolution."
Many leading participants such as Massoumeh Ebtekar, Abbas Abdi and Mohsen Mirdamadi have since developed into reformists highly critical of the conservative government of President Mahmoud Ahmadinejad, but reformists - like conservatives - remain highly critical of US foreign policy.
Mirdamadi, who played a key role in the embassy capture on November 4 1979, went on to head the influential national security and foreign policy committee of Iran's majlis (parliament).
He is now in prison accused of trying to topple the government.
Many attribute the failure of Jimmy Carter, US Democratic president from 1977 to 1981, to win a second term in office to his mismanagement of the hostage crisis when a failed rescue operation led to the crash of two aircraft and the deaths of eight American servicemen.
The 52 staff were released only in January 1981 following 444 days in captivity, just moments after Republican Ronald Reagan replaced Carter in the White House.
Washington broke off official relations during the crisis, a rupture that has yet to be healed. Iran still lauds the seizure as a revolutionary act while Washington condemns.
Nowadays the annual event opposite the former US embassy, known locally as the "Den of Spies," continues to draw a massive crowd.
They listen to a keynote speaker designated by the government, often someone who was not involved in the hostage-taking.
Iranian state-run television still broadcasts footage of the incident.
The embassy building, now under the control of Iran's elite Revolutionary Guards, is used as an educational centre where occasional exhibitions highlight the "crimes" of the United States.
This year the annual anti-US day could also be marked by street protests against Ahmadinejad, whose disputed re-election on June 12 triggered a political crisis in Iran.
Iran and the United States have not had diplomatic relations since 1979 Iranian revolution, which toppled the ruthless US-backed dictator, the shah.
Tehran never forgave Washington for supporting the shah.
US President Barack Obama admitted US involvement in the 1953 coup which overthrew the democratically elected Iranian government of Prime Minister Mohammad Mossadegh.
It was the first time a serving US president had publicly admitted American involvement in the coup.
The US Central Intelligence Agency, with British backing, masterminded the coup after Mossadegh nationalised the oil industry.
For many Iranians, the coup demonstrated duplicity by the United States, which presented itself as a defender of freedom but did not hesitate to use underhand methods to get rid of a democratically elected government to suit its own economic and strategic interests.
Washington went on to become the major backer of Shah Mohammad Reza Pahlavi, a brutal and ruthless dictator who was overthrown by the Islamic revolution of 1979.
Churches urge 'resistance' to Israeli settlements