"Their intention is to shake our will," Bush said last May in reaction to Nick's death. "We will complete our mission."
In response, Michael Berg said: "Nick died for the sins of the Bush administration."
In a speech at the rally, Berg, who almost always seemed on the verge of tears, said: "It's too late for my son, Nick, and it's too late for me, but it's not too late for you. ... Become a soldier in the nonviolent army and work for change."
More than 10 months after his son's death, Berg, a retired school teacher who lives in West Chester, Pa., a suburb of Philadelphia, has traveled around the world on a mission to oppose the war that claimed his son's life.
At first, Berg's family urged him not to speak out against the war. He said he had to struggle to balance his family's anger and pain over Nick's death with what he saw as a responsibility to speak out against the war.
It didn't take him long to realize, he said, "that this was bigger than just my family and there was an opportunity to show the people of the world the horror of war, and I never cared that people saw me at moments of emotional breakdown. I would have cared more if they hadn't seen me that way because people needed to see how much it hurts."
Berg said he never heard from President Bush following Nick's death, "but John Kerry called me."
While he supports the arrest of the men who killed his son, Berg said he also wants some U.S. officials held accountable for Nick's death.
"I do very much blame specifically George Bush and Donald Rumsfeld and Alberto Gonzales for my son's death, because aside from destabilizing the country so that the people they say killed my son could come in, they also thought up, researched the legal references for and gave the OK for the atrocities that took place at the Abu Ghraib prison. And the videotape of my son's death says that they killed him in retaliation for those atrocities.
"So I blame them, and I still blame them and I feel that even though I forgive, I have the right to blame them. I don't wish them any physical ill. I don't wish them any harm, psychological or otherwise. I do wish them to be disenfranchised of their power. I would like to see them be tried as war criminals, so I do seek justice and I think that is perfectly compatible with forgiveness."
As he spoke in a park several hundred miles from home, Berg was surrounded by friends. In North Carolina, Berg spent time with David Potorti, co-founder of 9/11 Families for Peaceful Tomorrows whose brother died in the World Trade Center attacks. Berg also knew many people from the group Military Families Speak Out, who have also suffered the losses of loved ones.
"All the people that are here are my support group," Berg said, looking at the people around him at the demonstration. "I have come to know most of the speakers that you heard here today.... It's a club that I'm an unwilling member of."