Zimmerman was the last U.S. ambassador to Yugoslavia

I first met Radovan Karadzic in the fall of 1990 during the campaign for the first free elections in Bosnia. He was visibly uneasy at accepting a restaurant lunch in Sarajevo from the American Ambassador; he was wary in appearance and guarded in comment. His manner of speech was low-key and courteous; but the content wasn't. As he explained, in paranoid terms, his conviction that the election was being rigged against his Serbian nationalist party, I formed two strong impression of him that stayed with me over our frequent subsequent meetings.

First, this was a man obsessed by the imagery of violence. Words like "war," genocide," "annihilation," and "hell" speckled his language. The world of his imagination and politics was a world of conflict in which Serbs were the eternal victims.

Second, Karadzic created a field of force around himself that radiated tension. Many Serbs have a sense of humor. Not Karadzic. This prophet of doom and disaster was deadly serious at all times.

Karadzic's philosophy, which he repeated to me like a broken record, was simple. Bosnian Serbs deserved to control most of Bosnian territory.

Confronted with the fact that they made up less than a third of the Bosnian population, he argued that they had been a majority in the past. "Serbian graves must be counted as well." He had no hesitation in inventing history to support his case, and he dealt in the crudest of racial stereotypes. Croats were "Nazis," Muslims were "Turks." Serbs on the other hand were generous, peaceful and incapable of hatred - a description that clashed with his obsessive celebration of conflict and war.

After about a year of seeing Karadzic, I came to believe that he was mad. His convictions about Serbian superiority and Muslim and Croatian perfidy surpassed the bounds of any human logic. His extolling of violence, made somehow more ominous by his soft-spoken style, transcended any objective that violence could achieve.

A psychiatrist himself, he seemed to me a man who needed psychiatric care, a person without moral compass or restraint.

Even before war broke out in Bosnia, he seemed a man capable of the genocide of which he accused his enemies. For me, he was the Heinrich Himmler of the Balkans.