The current exchange of charges and counter-charges between retired Gen. Sarath Fonseka and President Mahinda Rajapaksa must be particularly confusing to those Sri Lankans who consider both to be war heroes rather than war criminals. Many from the ethnic Sinhalese majority feel that, regardless of the human costs in the last months of the long-running civil war that ended last year, both leaders deserve credit for finally finishing off the terrorist Tamil Tiger rebels.

With the Sinhalese nationalist vote thus split, the two candidates are focusing their energies on winning the votes of the country’s minority ethnic Tamils — which is surely one of the stranger political ironies of early 2010. After all, both General Fonseka and Mr. Rajapaksa executed the 30-year conflict to its bloody conclusion at the expense of huge numbers of Tamil civilian casualties.

By early May, when the war was ending, the United Nations estimated that some 7,000 civilians had died and more than 10,000 had been wounded in 2009 as the army’s noose was being drawn tight around the remaining rebels and hundreds of thousands of noncombatants, who could not escape government shelling. The final two weeks likely saw thousands more civilians killed, at the hands of both the army and the rebels.

After the war, the Tamils’ plight continued. The government interned more than a quarter million displaced Tamils, some for more than six months, in violation of both Sri Lankan and international humanitarian law. Conditions in the camps were appalling, access by international agencies was severely restricted, and independent journalists could not even visit. Barbed wire and military guards insured people could not leave or tell their stories to anyone.

By the end of 2009, most of the displaced had been moved, and the nearly 100,000 remaining in military-run camps were enjoying some freedom of movement — important steps brought about mostly as a result of international pressure and the authorities’ desire to win Tamil votes. However, a large portion of the more than 150,000 people recently sent out of the camps have not actually returned to their homes nor been resettled. They’ve been sent to and remain in “transit centers” in their home districts.

Now, put yourself in a Tamil’s shoes, and decide whom to vote for in the presidential election: Choose either the head of the government that ordered the attacks against you and your family, or the head of the army that carried it all out.

On Jan. 4, the Tamil National Alliance, the most important Tamil political party, made its choice and endorsed General Fonseka after he pledged a 10-point program of reconciliation, demilitarization and “normalization” of the largely Tamil north. There is some hope his plan might be a sign that top leaders realize that, after decades of brutal ethnic conflict, peace will only be consolidated when Sinhalese-dominated political parties make strong moves toward a more inclusive and democratic state.

What counts more than campaign promises, though, is what the winner actually does in office, and based on past performance, it is hard to imagine either candidate making the necessary constitutional reforms to end the marginalization of Tamils and other minorities — the roots of the decades-long conflict. Left unaddressed, Tamil humiliation and frustration could well lead to militancy again.

While Sri Lankan voters face a difficult decision, for the international community, the choice is clear. Whoever wins, the outside world should use all its tools to convince the government to deal properly with those underlying issues to avoid a resurgence of mass violence. In the interest of lasting peace and stability, donor governments and international institutions — India, Japan, Western donors, the World Bank and the Asian Development Bank — should use their assistance to support reforms designed to protect democratic rights, tie aid to proper resettlement of the displaced, and a consultative planning process for the reconstruction of the war-ravaged, overly militarized north. U.N. agencies and nongovernment organizations should have full access to monitor the programs to ensure international money is spent properly and people receiving aid are not denied their fundamental freedoms.

In short, this means not giving Colombo any money for reconstruction and development until we know how it will be spent. And if we see funds not being used as promised, it means not being afraid to cut them off until.

While there may not be much to choose between the candidates, the rift between General Fonseka and Mr. Rajapaksa — and the consequent divisions among Sinhalese nationalist parties and the renewed vigor of opposition parties — has at least put the possibility of reforms on the agenda. International leverage, correctly applied, could help expand this small window for change, leading to the democratization and demilitarization the country desperately needs to move finally beyond its horrific war and its bitter peace.

Chris Patten is co-chairman of the International Crisis Group.