According to the news, what was the first real challenge for Mr. Baradei?

As director of the International Atomic Energy Agency (IAEA), the former Egyptian foreign ministry official has been committed to uncovering global nuclear threats. The seasoned 63-year-old diplomat has been at the center of non-proliferation crises concerning the three states President Bush has labeled as the "axis of evil"—Iraq, under the rule of Saddam Hussein, Iran and North Korea.
     Mr. ElBaradei has led the International Atomic Energy Agency at a time of transition. Once an agency mired in the bureaucratic task of monitoring nuclear sites worldwide, the IAEA soon became a key player in nuclear disarmament efforts around the world.
     The first real challenge for Mr. ElBaradei, who took the helm at the agency in 1997, was the agency’s inspections in Iraq, amid suspicions that Saddam Hussein was secretly developing nuclear weapons. His assertion in 2003 that there was no evidence of weapons of mass destruction in Iraq put him at odds with the United States, as it was preparing for war there.