Iraq’s future as a viable country may require an entirely new form of government unique in its power-sharing structure, a government that will survive only if the Iraqis adopt a useful political trick devised by Massachusetts Gov. Elbridge Gerry in 1812.

Time is running out. The United States probably will start withdrawing troops from Iraq early next year. More than likely, politicians will gravitate toward the Iraq Study Group’s recommendation to withdraw about half of the U.S. combat troops and use remaining forces to hunt down al Qaeda operatives, train Iraqi security forces and guard the Iraqi borders.

But even a modest withdrawal probably will trigger more violence, putting the remaining U.S. forces at greater risk. A better solution would be to announce plans to withdraw all U.S. forces. Getting it over quickly would limit U.S. casualties and provide the Shi’ite and Kurdish-dominated national government with a sober reality check that will force it to make needed concessions to the Sunni, which might prevent a winner-take-all civil war.

The main concession would be an agreement to decentralize the country, creating three semi-autonomous states—a Kurdish state in the north, a Sunni state in the center, and a Shi’ite state in the south, with the government in Baghdad responsible mainly for trade and economic affairs and the conduct of foreign policy.

Such a “confederation” would lessen fears that any one ethnic or religious group will gain control of the national government and oppress the others, as Saddam Hussein did. Although Iraq’s ethnic groups would all like to rule the country, none of them has the power to take over by force. By agreeing to powerful and autonomous regional governments—each responsible for its own security and most government services, such as education, health care and public works—the Sunni, Shi’a and Kurds would prevent their rivals from getting the prize.

Thanks to the oil wealth in the north and south, the Shi’a and Kurds would have little to lose from such an arrangement. The Sunni would have a lot to lose, since middle Iraq—the part they would control—has substantially less confirmed oil. So how do we get them to agree?

The key is known as “gerrymandering,” a political trick devised nearly 200 years ago in Massachusetts, when Gov. Elbridge Gerry created a political district that looked like a salamander (thus the term: gerrymander). In other words, in the official map of the new Iraq, boundaries would be creatively drawn to give the Sunnis additional oil fields, a much-more concrete arrangement than the mere promise of shared oil revenues.

A primary criticism of decentralization is that Baghdad and other large Iraqi cities are populated by various ethnic groups. That’s one of the beauties of gerrymandering: The regional boundaries could be drawn to incorporate the ethnic and religious enclaves in the cities, just as the 4th Congressional District around Chicago—known as the “earmuff” district, because of its shape—was drawn to include two Hispanic neighborhoods. Besides, the Iraqis themselves—not an outside power—would draw the boundaries, increasing support for the outcome.

A second concern is that creating an autonomous Iraqi Kurdistan might trigger a Turkish invasion, due to Turkey’s fear that such an entity would cause Turkish Kurds to secede. This scenario, however, is unlikely. Turkey desperately wants to get into the European Union and an invasion would give the Europeans good reason to reject it. Besides, after the Persian Gulf War in 1991, the Turks effectively accepted a de facto autonomous Iraqi Kurdistan and invested heavily in the region. They would not want to destroy those investments.

A third issue concerns Iranian influence in any Shi’ite autonomous region. Iran has influence over the Shi’ite-dominated Iraqi central government, which has jurisdiction over all Iraq. If Iraq is divided, Iranian influence would be limited to and even within the Shi’ite south.

Although it may be too late even for decentralization to save Iraq—because the ethnic and religious factions are splintering and the leaders may not be able to deliver their followers—this solution may be Iraq’s last best hope, the best among many bad alternatives.