The group, a coalition of anti-war and civil action groups called ANSWER urged Americans to "act now to stop war and end racism," and join a march on Washington on April 27 to persuade the Bush administration that Americans are opposed to further military action.
The group is also organizing resistance on college campuses against FBI orders that schools deliver the records and background on students from the Middle East and other countries the U.S. labels as terrorist states.
"To me it is the worst possible memorial you could have to those who died at the Pentagon and World Trade Center on Sept. 11th is to kill poor people in other countries by the thousands," Clark said.
He and other speakers decried the attacks in Afghanistan as having been more deadly to innocent Afghans than to Osama bin Laden. "You can't image the hardships they have been through for many generations," Clark said, which have been worsened by the U.S. bombing attack. "The real victims are the Afghan people," he said.
"Overwhelmingly you can see that the next probable victim is Iraq," he said. "You can feel the war fever and the lust."
Clark became a major critic of U.S. policy in Iraq during the Persian Gulf War in 1991 when he traveled to Iraq and with an independent film maker, shot what he says are the only "uncensored" film about conditions after Western bombing during the war.
He wrote "The Fire this Time: U.S. War Crimes in the Gulf."
Clark and several other speakers, including Bishop Thomas Gumbleton, Auxiliary Bishop, Catholic Archdiocese of Detroit and Kadouri al Kaysi, Committee in Support of the Iraqi People, said that the continued U.N. sanctions and repeated bombings of Iraq over a decade since the Gulf War have nearly destroyed the country's economy and fabric of life.
Al Kaysi said that hospitals have inadequate medicines, average incomes have dropped from $2,500 a year to $28 and thousands of children die annually from malnutrition and neglect. Schools have no books, decent buildings, or lecture equipment.
"Now we want to attack them again," Clark asked. "Is there no decency?"
2014: The Year in Music [PHOTOS]