Even if weapons of mass destruction are never found in Iraq, the U.S.-led war was justified because it eliminated the threat that Saddam Hussein (search) might again resort to "evil chemistry and evil biology," Attorney General John Ashcroft (search) said Monday.

Saddam's willingness to use such weapons was sufficient cause to overthrow his regime, Ashcroft told reporters, alluding to the use of chemical and biological arms against Iraqi Kurds in 1988 and during the 1980s Iran-Iraq war.

"Weapons of mass destruction including evil chemistry and evil biology are all matters of great concern, not only to the United States but also to the world community. They were the subject of U.N. resolutions," Ashcroft said.

"I believe there is a very clear understanding that Saddam Hussein continued to pose a threat," he said.

Ashcroft's comments came a day after David Kay (search), who resigned last week as America's top weapons inspector, pressed U.S. intelligence agencies to explain why their research indicated Iraq possessed banned weapons before the invasion.

Although the White House has insisted that illicit weapons eventually will turn up in Iraq, Vice President Dick Cheney and Secretary of State Colin Powell recently held open the possibility that they will not.

Ashcroft said terrorism remained a global menace and "we see no nations as immune to the Al Qaeda terrorist threat."

He spoke after meeting with Chancellor Wolfgang Schuessel, Interior Minister Ernst Strasser and Justice Minister Dieter Boehmdorfer on measures to fight terrorism and drug trafficking and improve air travel security.

On Tuesday, Ashcroft planned to visit a military base where Austria's elite Cobra police commando unit is based.

Cobra officers have been flying undercover aboard select Austrian flights to the Middle East in the past 20 years, and Austrian officials said Monday the unit will expand its training of U.S. air marshals.

After the Sept. 11, 2001, attacks, the United States expanded its force of air marshals, who are trained to stop hijackings. They wear civilian clothes and carry special bullets designed to kill without penetrating the metal skin of aircraft.

But the Bush administration's plans to require all foreign airlines to put armed agents on certain flights to the United States have drawn both support and skepticism in Europe.

Britain and France are receptive to the idea of sky marshals, but Denmark, Finland, Portugal and Sweden have signaled they would prefer grounding flights to deploying armed guards on planes if there were a strong suspicion of an attack. Several pilot organizations also have expressed reservations.

Because the EU's executive commission has no policing powers or legal means to negotiate on the continent's use of air marshals, Washington has had to deal individually with each EU nation.

Strasser called Ashcroft's visit "a very clear signal that Europe and the United States want to cooperate very closely on matters of security."