David Ignatius, in the Wa Po (5-4-05):

The most famous battlefield of the American Civil War might seem an unlikely place to look for lessons about Iraq. But as historian James McPherson leads a group of Pentagon officials in a discussion of postwar reconstruction, some startling common themes emerge....

To prepare for the discussion, McPherson guided the Army generals and Pentagon civilians along the rocky slope of Little Round Top to where the 20th Maine volunteers launched the mad bayonet charge that saved the Union army's flank, and then to the open field where Confederate Gen. George Pickett made his disastrous charge against the Union lines on Cemetery Ridge. After walking the battlefield, McPherson and the group explored what happened when the war ended -- and the intriguing parallels between postwar Iraq and the postwar South.

The Civil War, like the invasion of Iraq, was a war of transformation in which the victors hoped to reshape the political culture of the vanquished. But as McPherson tells the story, reconstruction posed severe and unexpected tests: The occupying Union army was harassed by an insurgency that fused die-hard remnants of the old plantation power structure with irregular guerrillas. The Union was as unprepared for this struggle as the Coalition Provisional Authority was in Baghdad in 2003. The army of occupation was too small, and its local allies were often corrupt and disorganized.

Reconstruction suffered partly because of a mismatch between a transformational strategy and haphazard tactics. Northern radicals such as Rep. Thaddeus Stevens wanted to break the old slaveholding aristocracy and remake the South into a version of New England, with former slaves and poor whites dividing up the plantations. But within weeks of Abraham Lincoln's assassination, President Andrew Johnson was moving to protect the privileges of the old regime. Even after Johnson was impeached, the government balked at enforcing the tough land-reform strategy evoked by the slogan "Forty Acres and a Mule."

For a time, it still seemed that reconstruction might work. "In 1870 things looked pretty good -- if not rosy, at least optimistic," says McPherson, who won a Pulitzer Prize for his 1988 narrative, "Battle Cry of Freedom." A black man was serving in the U.S. Senate and Northerners were investing in what they believed would be a new South.

But the insurgency was potent and took more than 1,000 lives. Along with the Ku Klux Klan, there were underground groups such as the White Brotherhood and the Knights of the White Camellia, determined to preserve the old regime's power. White insurgents staged bloody riots in Memphis and New Orleans in 1866. The rebels also drew support from the remnants of irregular Confederate units such as Quantrill's Raiders, which produced the outlaws Frank and Jesse James. "It was a matrix of lawlessness," says Oregon law professor Garrett Epps, who chronicles the period in a forthcoming book, "Second Founding."

The poison that destroyed reconstruction was racial hatred. The white elite managed to convince poor whites that newly freed blacks were their enemies, rather than potential allies. There's an obvious analogy to the Sunni-Shiite divide that has poisoned postwar Iraq. In the South, the die-hard whites began to believe that if they held tough, the North would abandon the campaign to create a new, multiracial South. And it turned out they were right.

By 1877, says McPherson, the North essentially gave up....

What lessons does this dismal history convey for U.S. forces in Iraq? First, what you do immediately after the end of hostilities is crucial, and mistakes made then may be impossible to undo. Don't attempt a wholesale transformation of another society unless you have the troops and political will to impose it. Above all, don't let racial or religious hatred destroy democratic political institutions as in the post-bellum South. Giving up on reconstruction led to a social and economic disaster that lasted nearly a century. That's a history nobody should want to repeat, least of all the Iraqi insurgents.