The United Nations, that much-maligned and much-misunderstood institution that has the potential to do much good for mankind, is at a crossroads.

The United States, its most powerful member-nation, can help reform it and make it better. Or it can sink it.

Traditionally, most Americans have supported the United Nations if for nothing else, its enormous achievements in the field of world health, aid to children, feeding the hungry and relief for millions of refugees.

A withdrawal from the United Nations now, for which some of the more extreme critics are calling, would clearly render it defunct.

It would also be immensely damaging to the United States at a time when the Bush administration is seeking to demonstrate its desire to work with the international community.

True, the United Nations can be a place of maddening bureaucratic torpor, and at times, as in the case of Iraq, of self-destructive political impotence. Its current image is hardly helped by an unfolding saga of corruption and managerial incompetence in the international oil-for-food program that enabled Saddam Hussein to siphon off billions of dollars for palaces and weaponry. Its embattled secretary-general, Kofi Annan, has been called on to resign by a U.S. senator (Minnesota Republican Norm Coleman).

In my time at the United Nations, Annan was the able and tough head of the U.N.'s widespread peacekeeping forces. Though he has made some injudicious remarks about the U.S. role in Iraq, and has been embarrassed by his son's ties to a company contracting with the United Nations, Annan deserves a postponement of judgment until the "full disclosure of the facts" about the oil scandal, for which President Bush has called, are at hand. Though one other senior U.N. official is under suspicion, the evidence so far points to officials in France and Russia as the principal culprits.

This underlines what is often misunderstood about the United Nations, namely that it is no more than an association of world nations, some of whom observe and practice its high-minded principles, some of whom do not. Some place self-interest above helping, or policing, others. Some lie. Some shamelessly manipulate.

But the collective effort has generally been more constructive than not in tackling humanitarian problems. As for war and peace, the United Nations has deterred some states from going to war, and kept the peace afterward between states who went to war and gave it up. From most of this the United States has benefited. In international peacekeeping operations, for instance, a multinational force saves billions of dollars over a unilateral U.S. operation.