The constructive give-and-take at the United Nations over a new U.S. draft resolution on Iraq should send a signal to anyone who is paying attention that the U.N. machinery is up and running — despite the best efforts of critics to relegate the organization to history’s ash heap of irrelevance.

In today’s challenging world, which finds itself both increasingly interdependent and twisted by multiplying tensions and troubles, the United Nations has more importance and necessity — indeed, indispensability — than ever.

If anything, the United Nations’ leadership, authority and power warrant reinforcement.

Such developments would not, by the way, threaten the sovereignty of the United States, for the United Nations bows to its members — not the other way around. Even the locus of power, the U.N. Security Council, makes decisions only with U.S. acquiescence.

Nor would an enhanced United Nations diminish the ability of an individual nation-state — whether the United States or another country — to pursue non-U.N.-blessed actions to defend its national-security interests.

But even when nations follow independent courses, such as in the case of the U.S.-led intervention in Iraq, the parties often find their way back to U.N. headquarters. Although critics are loathe to accept the reality, the United States needs the United Nations. The reason is simple: The United Nations stands as the most broadly acknowledged global source of legitimacy.

That status extends far beyond the Security Council through myriad agencies that underscore the U.N. role as an agent of change in dealing with issues from human rights to health to the environment.

Any number of proposals exist that aim to push the United Nations toward doing a better job. Three of them draw my attention:

First, broadening leadership in the Security Council. With five permanent members and 10 rotating ones, the council reflects the world of the mid-20th century more than the contemporary one. The council, in both its categories, should consider the world’s diversity, along with the surge in the number of nations. Japan and Germany frequently pop up as potential permanent members, but Brazil, India, Mexico, Nigeria and others deserve serious consideration.

Second, enhancing the United Nations’ authority. James Rosenau, a prominent analyst of international affairs, has written that the United Nations might “acquire greater authority by making its presence more visible and salient for people everywhere.” His idea is to ask every U.N. member to donate property in its capital for the placement of a permanent U.N. mission. That would expand the United Nations’ presence well beyond the existing offices of various U.N. agencies. The United Nations would provide personnel, tasks and operating funds to “prevent each mission from becoming too immersed in the affairs of the state-centric world” and monitor progress.

Every host country would pay an annual tax for the services of its mission. With the global economy in the doldrums, Rosenau’s proposal might not draw too many supporters these days. But permanent missions need not be extravagant and could serve a valuable function by sharing information and hosting events related to the United Nations.

Third, bolstering the United Nations’ power. One solution that would truly rile U.N. critics lies in giving the United Nations, an entity without armed forces, more muscle. That would enable the United Nations to respond more efficiently to problems such as civil wars and genocide. Former Secretary of State Madeleine Albright, writing in a recent issue of Foreign Policy, advocates “peace-enforcement missions authorized by the United Nations, in which the Security Council deputizes an appropriate major power to organize a coalition and enforce the world’s collective will. The council sets the mandate, but the lead nation calls the shots.”

Why not go a step further and create a permanent, rapid-deployment, peacemaking force for the United Nations? I’m not suggesting a standing military; rather, various nations would commit troops that could mobilize quickly.

In evaluating those and other proposals, the emphasis belongs on enhancing the United Nations — not trying to sideline or abolish it.

John C. Bersia won a Pulitzer Prize in editorial writing for the Orlando Sentinel in 2000 and is special assistant to the president for global perspectives. His e-mail address is jbersia@orlandosentinel.com.