Historian Peter Winn has argued that the role of the CIA was crucial to the consolidation of power that followed the coup; the CIA helped fabricate a conspiracy against the Allende government, which Pinochet was then portrayed as preventing. He states that the coup itself was possible only through a three-year covert operation mounted by the United States. He also points out that the US imposed an "invisible blockade" that was designed to disrupt the economy under Allende, and contributed to the destabilization of the regime. Peter Kornbluh, director of the National Security Archive's Chile Documentation Project, argues in his book "The Pinochet File" that the US was extensively involved and actively "fomented" the 1973 coup. Authors Tim Weiner, in his book, "", and Christopher Hitchens, in his book, "The Trial of Henry Kissinger" similarly argue the case that US covert actions actively destabilized Allende's government and set the stage for the 1973 coup. Joaquin Fermandois criticized Kornbluh's "black and white" and "North American centered conception of world affairs", stating that a variety of internal and external factors also played a role and that a careful reading of the documentary record reveals the CIA was largely "impotent".