On Tuesday, conservative icon David Horowitz released his newest tome, a compendium of his works on communism titled The Black Book of the American Left. Peter Collier, vice president of publications at the David Horowitz Freedom Center, writes describes The Black Book of the American Left as a collection of “all of Horowitz’s conservative writings over the last thirty years.”

In the preface to the book, Horowitz describes how “the primary focus of my work…has remained one big thing: the nature, deeds, and fortunes of the political left.” As a former New Left member, Horowitz knows the left inside and out, and acknowledges that he may have an “obsession.” “I had left the left, but the left never left me,” he writes. “For better or worse, I have been condemned to spend the rest of my days attempting to understand how it pursues the agendas from which I have separated myself, and why.”

Unlike some of the right, Horowitz sees leftism as the true threat to America, not mainstream liberalism. As he says:

The massive defeat they…suffered in the fall of the Marxist states they helped to create had the ironic and unforeseen effect of freeing them from the burden of defending it. This allowed them in the next decade to emerge as a major force in American life. In the wake of the Communist collapse, this left has become a very big thing – so big that by 2008 it was the dominant force in America’s academic and media cultures, had elected an American president, and was in a position to shape America’s future.

Horowitz sees his mission as twofold: persuading those on the left that their ideas are pernicious and destructive, and expressing to conservatives the urgency of fighting the left rather than sitting on their haunches. Horowitz objects to terming leftists liberals: “In calling them liberals, [conservatives] failed to appreciate the Marxist foundations and religious dimensions of their radical faith or the hatreds it inspired.”