United Nations ? In a recent speech, Hans Blix told his weapons inspectors exactly how to act in Iraq: Be driving and dynamic, but not angry and aggressive. Show some flexibility, but don’t be pushed around.

He could have been describing himself.

The 74-year-old Swede is charged with telling the world whether Iraq has biological and chemical weapons and is complying with U.N. inspections. His report may not halt the United States’ plans for war with Iraq, but it will likely make or break international support for it.

He comes to the job with years of experience, but mixed reviews. “Extremely prudent, careful and courageous,” says former U.S. diplomat Richard Gardner, an old friend. “Totally incompetent,” says Per Ahlmark, Sweden’s former deputy prime minister.

But for the U.N. Security Council, Blix was the right person at a difficult time.

In January 2000, he became the compromise candidate for chief U.N. weapons inspector after Washington’s pick ” another Swede ” was rejected by a badly divided council.

At the time, inspectors had been out of Iraq for more than a year, and there was no sign they would be allowed to go back.

Still, Blix, an international law expert who previously ran the U.N. nuclear watchdog agency, set out to reshape the inspections regime, whose reputation had been tainted by abrasive tactics and allegations that inspectors spied for the United States and Israel.

As chief weapons inspector for the United Nations, Hans Blix is charged with telling the world whether Iraq has biological and chemical weapons.

His first move was to hire Demetrius Perricos, a Greek nuclear expert who had been his deputy at the International Atomic Energy Agency in Vienna. Together, they turned to alternative intelligence sources rather than relying heavily on Washington’s data.

Blix’s office ” the U.N. Monitoring, Verification and Inspection Commission ” followed its orders to the letter, hiring a new international crew of technical experts and inspectors. Meanwhile, Blix built a close relationship with Secretary-General Kofi Annan and made clear his allegiances were strictly to the Security Council, which oversees his mission.

The diplomatic maneuvering won him accolades for maintaining a tough, neutral yet businesslike approach to the job while he waited patiently for a way back to Baghdad.

The opportunity came this September when Iraq, under enormous international pressure generated by President Bush’s tough challenge to the U.N. General Assembly, agreed to the unconditional return of inspectors.

Now Blix is armed with a new Security Council resolution that broadens his powers. He’s reluctant to overdramatize his role, rejecting the notion that “we hold war and peace in our hands,” but clearly his report card on Iraqi compliance will be the deciding factor for many U.S. allies unsure about another conflict with Iraq.

“The burden will be on Hans and what kind of a report he’ll present to the council,” said Gardner, a former ambassador who teaches international law at Columbia University ” where he and Blix met 40 years ago.

Gardner is confident in Blix, saying, “Anyone who thinks he can be pushed around is wrong.”

Not everyone agrees.

“He’s not strong enough to be the head inspector in a tyranny of Saddam Hussein,” said Ahlmark, who entered Swedish politics with Blix years ago. “It’s much too important a job for him and he’s too easily deceived.”

Blix will be tested from the outset by what kind of sites he chooses to inspect, how aggressively he pursues his orders and whether he can solve a decade-old mystery about Iraq’s weapons programs.