The UN World Food Program will distribute 331,000 metric tons of corn and other staples in Zimbabwe by 2007, nearly a third of all the donations it plans for southern Africa. The United Nations is building 2,500 shelters in Harare, the capital, to house the homeless. Such generosity is welcome, but its subtext raises wrenching ethical issues. For in the view of critics, these humanitarian gestures will not simply save lives and ease misery, though they will surely do that. The critics say that the aid also will bolster Zimbabwe's authoritarian regime, which razed and burned the homes of those 700,000 citizens earlier this year and commanded them to move into the countryside. President Robert Mugabe calls the demolitions slum clearance. Critics call it a plot to disperse the same impoverished Zimbabweans who pose the greatest threat to Mugabe's 25-year rule. Most UN food aid is being funneled, at Zimbabwe's insistence, into rural areas. While that need is great, the effect is to deny aid to those poor who have lost their homes but who resisted being relocated to rural areas. Zimbabwe's rulers have also refused to let the United Nations erect tents or other temporary shelters that might make it easier for those whose homes were razed to remain in the cities. The world's aid to Zimbabweans is part of a devil's bargain, critics say: Save the poor from hunger and exposure, but at the price of aiding the very rulers who are making them hungry and exposed in the first place. Should such deals be struck? Implicitly and otherwise, they are struck all the time: In Darfur, relief organizations might be said to have aided the Sudanese government's ethnic cleansing merely by providing assistance to refugee camps set up by the victims of that cleansing. While refugees are fed and housed far away from their homes, the government can consolidate its hold on their former territory. North Korea demanded this month that international food donors leave the country by year's end, ratcheting up its leaders' efforts to stop outsiders from monitoring the delivery of the food to its starving citizens. In Bosnia, Rwanda and dozens of other crises, humanitarian agencies have been faced with the prospect that their good deeds could redound to the benefit of those who created the human suffering they sought to address. Such moral dilemmas hardly overshadow the lifesaving work that relief agencies perform. But the dilemmas are not trivial. Since the Cold War ended, humanitarian responses to wars and political crises have mushroomed, sometimes supplanting more muscular diplomatic and military actions of years past. Sending aid, it seems, is easier, warmer and fuzzier than tackling the root problems that led to the crisis at hand. As relief has become a preferred response to problems like refugee crises, dictators and warlords have become ever cannier at exploiting that aid. And the dilemmas have become more common and thornier. "It's one of the conundrums that humanitarian organizations face," Larry Minear, the director of the Humanitarianism and War Project at Tufts University in Boston, said in a telephone interview. Such tradeoffs, he said, have provoked debate over whether there are times when "one should withhold assistance in the interest of whatever overall objective there might be - including an end to the particular conflict that might be creating the need." Rarely, agencies do withhold assistance. After the Rwanda genocide of the mid-1990s, the International Rescue Committee pulled its workers out of refugee camps in Congo after concluding that soldiers behind the genocide were using the camps to regroup for further attacks. "We just decided we would not be complicit," George Rupp, the organization's current president, said in a telephone interview. But, he acknowledged: "That was a very complicated decision, one that continues to reverberate around the IRC. The result was that there were people with real needs that were not met." In almost every case, agencies swallow hard and offer help anyway, arguing that the greater good of saving lives and reducing suffering outweighs the ignominy of being a handmaiden to oppression. One option, experts say, is for relief agencies to publicize their devil's bargains - to show the world how such blackmail works, potentially shaming those responsible. Another is to press wrongdoers, publicly and in private, to stop rights abuses that humanitarians can document. Relief agencies have historically been loath to do that for fear that angry governments will bar them from helping the victims. A theologian in Geneva, Hugo Slim, believes that this fear is overrated; even evil rulers, he says, are usually reluctant to do much more than hector those who bring aid. Slim, the chief scholar at the Center for Humanitarian Dialogue, said in an interview that relief agencies could be creative in expressing themselves, perhaps by persuading moral authorities further removed from the crisis to speak for them. In Zimbabwe, for example, the World Food Program and the UN Development Program have said little about the constraints. But top UN humanitarian and housing envoys have been scathingly critical of Mugabe's slum-demolition program and have demanded that relief agencies be given wider leeway to aid its victims. Humanitarian organizations can also be subversive. Even if they are sharply limited in their own efforts, relief workers can strike quiet alliances with local activists, leverage their influence with sympathetic government insiders and educate those they are helping about their rights. If all else fails, Slim, Minear and others agree, the last resort - halting aid and withdrawing - remains. Even then, Slim said, it is vital to explain the decision to the needy and seek their "informed consent." Such efforts shield aid agencies from charges of desertion, and preserve the bond between benefactor and recipient that is at the heart of humanitarian efforts.