Saddam Hussein allowed the world to believe he had weapons of mass destruction to deter rival Iran and did not think the United States would stage a major invasion, according to an FBI interrogator who questioned the Iraqi leader after his capture.

Saddam expected only a limited aerial attack by the United States and thought he could remain in control, the FBI special agent, George Piro, told CBS's "60 Minutes" program in an interview to be broadcast Sunday.

"He told me he initially miscalculated ... President Bush's intentions," said Piro. "He thought the United States would retaliate with the same type of attack as we did in 1998 ... a four-day aerial attack."

"He survived that one and he was willing to accept that type of attack," Piro said.

The Associated Press spoke to a close aide of Saddam's in August 2003, who said that Saddam did not expect a U.S. invasion and deliberately kept the world guessing about his weapons program, although he already had gotten rid of it.

Saddam publicly denied having unconventional weapons before the U.S. invasion, but prevented U.N. inspectors from working in the country from 1998 until 2002 and when they finally returned in November 2002, they often complained that Iraq wasn't fully cooperating.

Piro, a Lebanese-American who speaks Arabic, debriefed Saddam after he was found hiding in an underground hideout near his home city north of Baghdad in December 2003, nine months after the U.S. invasion.

Piro said Saddam also said that he wanted to keep up the illusion that he had the program in part because he thought it would deter a likely Iranian invasion.

"For him, it was critical that he was seen as still the strong, defiant Saddam. He thought that (faking having the weapons) would prevent the Iranians from reinvading Iraq," Piro told Scott Pelley of "60 Minutes."

Piro added that Saddam had the intention of restarting an Iraqi weapons program at the time, and had engineers available for chemical, biological and nuclear weapons.

Piro also mentioned Saddam's revelation during questioning that what pushed him to invade Kuwait in 1990 was a dishonorable swipe at Iraqi women made by the Kuwaiti leader, Sheik Jaber Al Ahmed Al Sabah.

During the buildup to the invasion, Iraq had accused Kuwait of flooding the world market with oil and demanded compensation for oil produced from a disputed area on the border of the two countries.

Piro said that Al Sabah told the foreign minister of Iraq during a discussion aimed at resolving some of those conflicts that "he would not stop doing what he was doing until he turned every Iraqi woman into a $10 prostitute. And that really sealed it for him, to invade Kuwait," said Piro.