Peter Gowin (Former U.S. Ambassador to Iraq): This tape was made by the Iraqi security services.
A tape that may help to explain a lot about what's happening today in Iraq.
Peter Gowin: Mass killers do turn out to be bureaucrats. Nazi Germany kept its records; Saddam Hussein has kept its records.
And this is one of those records. A tape of the execution of Kurdish dissidents. One of the countless acts of brutality ordered by Iraq's most feared general. The general who is now leading the resistance to U.S. forces in the south of Iraq.
Peter Gowin: His nickname is "Chemical Ali."
Chemical Ali, swearing allegiance to Saddam Hussein, and so named because he is the general who, with great zeal, carried out chemical attacks years ago against Saddam's opponents.
Peter Gowin: He is Saddam Hussein's cousin. He's Saddam Hussein's right-hand man.
Former U.S. Ambassador Peter Gowin first turned up the evidence of Chemical Ali's activities more than 12 years ago when he went to Iraq.
Peter Gowin: This is an incredibly cruel figure. This is a man who knows how to martial all the instruments of terror and cruelty to promote his objectives. And I think he's doing it today in the south of Iraq.
And people throughout Iraq know what Chemical Ali will do to those who stand in his way.
Peter Gowin: You can see here the crowd that's been forced to turn out for these executions.
Brian Ross: Children in the crowd?
Peter Gowin: Yes, there are children watching this.
A message not to defy Saddam's rule. After the executions, a final indignity.
Peter Gowin: All the officials come to each of them and put a bullet into the body. Everybody then bonds together in committing these acts. This video is just the tip of the iceberg.
But it was the chemical attacks ordered by the General which forever altered the scale of evil in Iraq, and now serve as a warning to U.S. and British troops.
Katrine Michael (Former Iraqi Citizen): Children, women, men vomiting screaming, crying with swollen eyes.
Katrine Michael described the ordeal to Barbara Walters.
Katrine Michael: They were screaming, we are blind, we cannot see.
Two hundred fifty Kurdish villages in Northern Iraq were attacked. The victims left lying in the streets where they died fleeing from the clouds of gas.
Peter Gowin: They were experimenting with the lethality of different kinds of chemical weapons. Mustard gas, cyanide, nerve agents, women, children, men. They were the guinea pigs in these experiments.
The General has denied any involvement, but on this audiotape he is heard planning the attacks.
General "Chemical Ali": I can say we'll hit them with the chemicals and kill them all. Who is going to say anything? The international community? To hell with the international community and all those who listen to them.
Peter Gowin: The analogies to the Nazis are uncanny.
And now, those in Iraq who survived the chemical attacks are the living testament of the tactics of Chemical Ali.
Professor Christine Godsen (University of Liverpool): This is the world's largest population ever exposed to weapons of mass destruction.
All victims of the Iraqi general whose genocidal tactics were overlooked by the U.S. when it supported Iraq over Iran, according to former CIA agent Bob Baer, now an ABC News consultant.