United Nations chemical and biological weapons inspectors "are ready to go as soon as we are asked" into Iraq, a senior U.N. official said, making the case that the United States could benefit more than ever today from greater global cooperation.

Much of the world "would set great store on an international weapons inspection finding" of possible hidden stockpiles in Iraq, U.N. Undersecretary-General Shashi Tharoor of India said in an interview. Such a finding could give "some closure" to the controversy on weapons of mass destruction, he said.

But a greater U.N. role in Iraq and beyond requires a greater appreciation by U.S. officials "of the extraordinarily valuable contributions" the U.N. can make, Tharoor said. The U.N. nuclear weapons inspectors who just arrived in Iraq, he said, "have been restricted in what they're being allowed to see" by occupying U.S. forces.

"We can only do what we are allowed to do," said Tharoor, who is in Denver to speak to the national and international mayors conference.

The push to revive the U.N. effort reflects top-level concern at a time when public confidence in the U.N. is falling. Majorities in the United States and 19 other countries viewed the U.N. as "less important" after the Iraq war, according to a Pew Global Attitudes Project survey. Critics contend that the U.N. founders' dream - of international law limiting the use of force - now is giving way to individual nations fending for themselves.

"I don't believe the United States can look much to the U.N. for our security problems. They are just not competent for that," said Jeane Kirkpatrick, who served as U.S. ambassador to the United Nations from 1981 to 1985. U.N. leaders have overreached, Kirkpatrick said. And, in her view, the U.N. Security Council in the future will play a less active role - a forum "to facilitate action" by member states when they want, she said, but seldom acting on its own.

Others counter that the U.N., founded in 1945, is crucial today. The body represents "the only place the world can come together to pool strengths and share burdens," said Tim Wirth, director of the U.N. Foundation, which funds efforts to address global problems such as poverty and water scarcity.

Beyond credible weapons inspections in Iraq, the United States could benefit from a broad U.N. role in the war on terrorism, Tharoor said. After the Sept. 11, 2001, attacks, a single U.N. resolution laid the legal foundation for a U.S.-led campaign to scrutinize international arms transfers and money-wiring and to share police intelligence across borders, he said. For U.S. officials to have done that without the U.N. Security Council "would have taken decades" of country-by-country treaty negotiations, he said.

Now, he said, the U.N. can provide crucial help in addressing root causes of terrorism among people who feel threatened and vulnerable. U.N. agencies can help create jobs and introduce anti-hate school programs that could counter the influence of "Koran and Kalashnikov" ideology that fosters terrorism, he said. "There will always be nasty people who want to use terrorism as a means. But economic development, education, these are important shields."

The U.N. Security Council also can send peacekeeping forces to stop the worst conflicts from "descending into hell," he said. During the 1990s, the U.N. deployed as many as 80,000 peacekeepers. Today, half as many are active, and the force in the middle of Africa's worst war numbers only 5,000 - "too small to succeed, to large to hide," Tharoor said.

In the future, he said, militaries in the United States and other wealthy nations could earmark troops with relevant experience for rapid deployment on U.N. peacekeeping missions.

"The United States does not have to do everything," Tharoor said. "It just has to uphold a system in which others can act."

The alternative to a U.N. system is "to go back to the horrors of the 20th century" from nuclear bombs on Japan to genocides, he said. Some U.S. officials resist a greater role for the U.N. in Iraq.

"We just deployed a (U.S.) team of 1,500 experts including some former U.N. weapons inspectors," a Department of Defense spokesman said Friday. Their search for chemical and biological weapons stockpiles in Iraq "will take some time," the spokesman said.

The spokesman, who declined to speak on the record because Defense Secretary Donald Rumsfeld has not yet addressed the matter, also questioned Tharoor's assertion that U.N. nuclear inspectors in Iraq are restricted.

President Bush and his senior advisers seesaw between supporting the U.N. "because it provides a kind of international legitimacy that is very difficult to get otherwise" and wanting to pursue U.S. interests unilaterally, said Jonathan Tepperman, an international-law expert and senior editor of the journal Foreign Affairs. U.S. leaders generally "have started to recognize that the U.N. can be very useful," he said.

Americans see benefits of the U.N. daily, Tharoor said. Those who travel abroad count on safety that comes from a U.N.-set rule that pilots speak English. At home, they count on U.N. efforts to detect and control the spread of diseases across borders. Even watching TV, they count on a U.N.-run system for coordinating satellite communications, he said.