Why stop with Iraq?

If the US persists in enforcing regime change in Iraq, why not do so in every country where the ruler is odious and grossly mistreats his or her people?

Among the many possible candidates for regime change are the cruel despots of Belarus, Burma (Myanmar), Cambodia, Equatorial Guinea, Liberia, North Korea, the Sudan, and Zimbabwe. If intervening in Iraq might take a few weeks and 400,000 troops, ousting some of these less formidable oppressors might need as little as a lunch hour and a small detachment of marines.

Admittedly, Iraq is in a category of its own. Intelligence suggests that it possesses biological and chemical weapons capacity, and, once it secures fissile material, might be able to construct a nuclear device. Aside from North Korea, none of these other places harbors weapons of mass destruction.

Yet, in each case, these rulers possess and have used weapons of destruction against their own people, causing the immiseration of millions. President Charles Taylor in Liberia, for example, has long embroiled his country and neighboring Guinea and Sierra Leone in crippling wars. The military rulers of Burma have insistently employed forced labor to build pipelines and roads, greatly impoverished their people, and refused to abide by the prodemocratic results of the 1990 election. The Sudanese government bombs its own (rebellious) citizens in the south, and has done so systematically for 19 years.

Several if not all of the other places hold their own people in as much or more contempt than Saddam Hussein does his citizens. President Robert Mugabe in Zimbabwe, for example, is now letting about half his population – a full six million people – starve.

According to a UN special rapporteur's account in late September, standards of living in Iraq have recently improved; the quality of life in Iraq appears much better than in most of the other countries on our possible hit list.

But in Zimbabwe, in North Korea, and in almost all of the other places, living conditions remain exceedingly difficult.

If Washington is truly prepared to play policeman of the world on behalf of human rights concerns, and to prevent rulers from repressing their own citizens, we need a new political doctrine and a carefully enunciated set of criteria for action. If the US is truly ready to contravene international law and the UN charter, we need to decide whether it is only resource-rich states that are subject to attack, or if poorer autocracies also receive close American attention.

Alternatively, if preemptive strikes are to be launched only when rogue states possess weapons of mass destruction and are prepared to use them against the US or its allies, then we need a different doctrine, a method of ascertaining sure intent, and a means of ensuring ourselves that the weapons are armed and poised. Under this last rubric, Washington might be compelled to act against Pakistan or India, or both.

Clearly there is dissonance. Washington can only justify attacking Iraq and not Zimbabwe because of weapons of mass destruction, possible links to Al Qaeda, oil, and politics. Yet Zimbabwe (and Burma, Liberia, the Sudan, etc.) are the clearer cases and, in some ways, the easier cases.

Whereas Mr. Hussein used poison gas against the Kurds more than a decade ago, and started the foolish assault on Kuwait in 1990, Mr. Mugabe is torturing opponents now, depriving literally millions of food, and destroying his country's entire capacity to prosper.

Whereas Iraq's GDP per capita is growing, Zimbabwe's has fallen by about 20 percent in two years. Liberia is a failed state where the people continue to suffer from Taylor's greed and constant warfare. All of the new oil wealth of Equatorial Guinea is going into the hands of President General Teodoro Obiang Nguema. Alexander Lukashenko, in Belarus, behaves arbitrarily, like Mugabe, but with fewer convenient scapegoats. Hun Sen runs a punishing operation in Cambodia, as the military junta does in battered Burma.

Each of these hapless and abysmally run countries merits intervention. Why not remove their rulers, and demonstrate to the world that the US means business?

It may be much more salutary to bully with a broad, all-encompassing sweep than to focus only on the Middle Eastern country with the most oil, a legacy of having survived Desert Storm, and a ruler who has thumbed his nose at Washington and its presidents.

• Robert I. Rotberg is director of Harvard University's Program on Intrastate Conflict at the Kennedy School and president of the World Peace Foundation.