O'Neill predicted that his former colleagues -- one of whom has already tried to paint him as a disgruntled former employee with a "tin ear" for politics -- would hit back.
"These people are nasty and they have a long memory," O'Neill told Time.
Democrats vying for the chance to challenge Bush in November jumped on O'Neill's comments.
Former Vermont Gov. Howard Dean, whose opposition to the invasion of Iraq has boosted him to the front ranks of Democratic candidates, said the Suskind book shows Bush "planned to go to war all along."
Sen. Joseph Lieberman of Connecticut, who backed the decision to go to war in Iraq, said O'Neill's concerns about Bush's economic programs were right.
"This administration has taken us into the largest fiscal deficit in our history," Lieberman told "Fox News Sunday."
"The dollar is at an all-time low, and 3 million people lost their jobs. Last month, when the administration said we'd expect to see 150,000 new jobs created, we ended up seeing 1,000 -- a very lame performance."
