This is the pre-eminent task that will confront the next UN secretary-general, a post for which I and three others so far are candidates. We need reform not because the United Nations has failed, but because it has succeeded enough over the years to be worth investing in. Mahatma Gandhi once said, "You must be the change you wish to see in the world." The United Nations, where I have worked for the last 28 years, is no exception. If we want to change the world, we must change too.

The single greatest problem facing the United Nations is that there is no single greatest problem -- rather, there are a dozen different ones each day clamoring for attention. Some, like the crisis in Lebanon, the Palestinian situation and the nuclear programs in Iran and North Korea, are obvious and trying. Others we call "problems without passports" -- issues that cross all frontiers uninvited, like climate change, drug trafficking, human rights, terrorism, epidemic diseases, and refugee movements. Their solutions, too, can recognize no frontiers because no one country or group of countries, however rich or powerful, can tackle them alone. The key to all of them is strengthening the capacities of both the United Nations and its members. Here's how:

Make democracy a priority: There is much at the United Nations that must continue -- our excellent work in humanitarian relief and crisis response, and in social and economic development, to take a few examples. But we must make a greater effort to promote democracy and good governance as key ingredients of development. We now have a Democracy Fund to help us do that, financed not just by the rich West but by countries like India. To that end the United Nations must also stand up for human rights everywhere, ensuring that the new Human Rights Council fulfills its responsibilities more effectively than the over-politicized Human Rights Commission it replaced. And we must not let conflicts reignite when peacekeepers have left: we must strengthen the newly created Peacebuilding Commission to ensure that conflict gives way to development and the creation of democratic institutions so that peace is truly sustainable.

Bolster the ranks: We have to make a difference where it counts -- in the field, not just in the conference rooms in New York and Geneva. No task is more important than reinforcing the United Nations' operational capacity -- to fulfill the Millennium Development Goals (a set of promises to improve the lives of billions by 2015, which for the most part are not on course to being met), to mount effective peacekeeping operations (which currently take too long to deploy and are uneven in quality) and to respond urgently to humanitarian crises. (I know from my own experience with refugee work that we are doing well there, but can become the gold standard for emergency relief.) As head of the United Nations, I would strengthen the international civil service, eliminating the nepotism and cronyism for which we have sometimes justifiably been blamed. And I would work together with Washington on the unfinished business of management reform, especially to ensure ethics, accountability and transparency, together with truly independent audit oversight.

Prioritize and streamline: The United Nations must be more sharply focused on areas where it has a proven and undoubted capacity to make a difference -- when major humanitarian disasters strike, peace must be kept or territories administered. But where others have the capacity, the resources and the will to keep the peace -- NATO in Afghanistan, the European Union in Bosnia, though not yet the African Union in Darfur -- the United Nations should bless their efforts. And where the task, like enforcing peace in Iraq, is clearly beyond us, we should let wars be fought by warriors, not peacekeepers.

Heal wounds: There's a great danger of the East-West divide of the cold war being replaced by a North-South divide at the United Nations, as developing countries resist what they see as a rich-country agenda. The new secretary-general must urgently combat this. I would focus on building issue-based coalitions to deal with specific practical problems (things like management inefficiencies, procurement policies, information technology, outsourcing) that have little to do with ideological politics.

At the same time, let us never forget that the United Nations will only succeed as a recourse for all and not the instrument of a few. It must amplify the voices of those who would otherwise not be heard, and serve as a canopy beneath which all can feel secure. As our great second secretary-general, Dag Hammarskjold, put it, the United Nations was not created to take mankind to heaven, but to save humanity from hell. That it has, so far, but not all the time and not everywhere. We can do better. Indeed, at this time of turbulence and transformation, we must.

Shashi Tharoor is undersecretary-general of the United Nations.

(c) 2006, Newsweek Inc. All rights reserved. Reprinted by arrangement.