U.N. weapons inspectors are back in Iraq after a four-year hiatus. An advance team of about 30, accompanied by Mr. Hans Blix, head of the U.N. Monitoring, Verification and Inspection Commission, and Mr. Mohamed ElBaradei, director of the International Atomic Energy Agency, arrived in Baghdad on Monday aboard a chartered flight. Formal inspections are expected to begin on Nov. 27 following consultations with Iraqi officials and logistic preparations.

The inspectors will be working under the shadow of a threatened U.S. strike against Iraq. But war is not inevitable, Mr. Blix said, if Iraq cooperates with them in earnest. It is hoped that Baghdad will provide full cooperation, with no strings attached. The United States, for its part, should fully support this opportunity to avoid war by ensuring that the inspections are thorough.

UNMOVIC, created in 1999, must set an example of effective arms inspection. Its predecessor, the U.N. Special Commission, or UNSCOM, which was charged with destroying Iraq's weapons of mass destruction, was disbanded because of systematic obstruction by Baghdad. Using various tricks and ploys, the Republican Guard, an elite force tasked with protecting President Saddam Hussein and defending the Iraqi capital, kept inspectors away from the sites where Iraq was hiding related materials, equipment and data. Baghdad blamed UNSCOM for harboring American spies.