"Iran has already started down the road to genocide," said human rights lawyer and Canadian MP Irwin Cotler, at a conference here Tuesday ahead of Iranian President Mahmoud Ahmadinejad's appearance at the UN later in the day.

Pointing to the International Convention on the Prevention and Punishment of the Crime of Genocide's article criminalizing "public incitement to commit genocide," Cotler argued that Ahmadinejad's threats toward Israel and insults about the Jewish people violated the covenant.

"The crime of incitement to genocide has already been committed," Cotler told the conference against state-sponsored genocide, sponsored by The Jerusalem Center for Public Affairs and other organizations.

He cited Ahmadinejad's demonization of Jews by calling them "bloodthirsty barbarians" and worse, together with his calls for the destruction of Israel.

"Iran has paved the way to genocide, and genocide has already begun in [the sense of] incitement," he said.

For those who would dismiss such statements, former US ambassador to the UN Richard Holbrooke, who also spoke at the conference, stressed that "words matter."

Holbrooke noted that his own grandfather decided to move his family out of Germany in the 1930s when he read Adolf Hitler's Mein Kampf and took its message seriously - something that many other German Jewish families who ended up perishing in the Holocaust did not do.

"What you say today can turn into a policy tomorrow," warned Holbrooke, the architect of the Dayton accords, which ended the war in Bosnia in 1995.

Esther Mujawayo learned that lesson first-hand as a victim of the Rwandan Genocide of 1994, an experience she recounted at the conference.

She recalled that the genocide's perpetrators stated their intentions openly, and yet nothing was done because the international community lacked political will, a situation she doesn't want to see repeated.

Referring to Iranian designs, she said, "Let us unite - I think that's not a vain word - to stop them in time."

At the gathering, Cotler unveiled a petition urging states to fulfill their obligations as signatories to the convention and act against Ahmadinejad's incitement to genocide.

Such action should include asking the United Nations to investigate his statements, Cotler said, as the convention allows. And yet, he noted, up until now not one state had filed such a complaint.

"We have a chance now to prevent a genocide," he said. "Now is the time to act."