"The administration wasn't matching its deeds to its words in the war on terrorism. They're making us less secure, not more secure," said Beers, who until now has remained largely silent about leaving his National Security Council job as special assistant to the president for combating terrorism. "As an insider, I saw the things that weren't being done. And the longer I sat and watched, the more concerned I became, until I got up and walked out."

Nevertheless, Beers will say that the administration is "underestimating the enemy." It has failed to address the root causes of terror, he said. "The difficult, long-term issues both at home and abroad have been avoided, neglected or shortchanged and generally underfunded."

The focus on Iraq has robbed domestic security of manpower, brainpower and money, he said. The Iraq war created fissures in the United States' counterterrorism alliances, he said, and could breed a new generation of al Qaeda recruits. Many of his government colleagues, he said, thought Iraq was an "ill-conceived and poorly executed strategy."

"I continue to be puzzled by it," said Beers, who did not oppose the war but thought it should have been fought with a broader coalition. "Why was it such a policy priority?" The official rationale was the search for weapons of mass destruction, he said, "although the evidence was pretty qualified, if you listened carefully."