"I have a very heavy sense of responsibility because I was one of the senior ministers who made or recommended that decision to the House of Commons," Straw said in an interview with Sky News.
"There were some incompetent decisions made subsequently. The most incompetent, about which we were not consulted…, was the way in which the decision to ‘debaathify’ the Iraqi army was taken," he added.
The Labour minister called the US policy, which barred Sunnis of Hussein's minority government from senior government and military positions, a "terrible example of disfunctionality inside the American system."
Straw said this decision created over a million people with weapons and military training but no salary, which laid the ground for sectarianism in post-war Iraq, governed by the Shiite majority.
