An interview with Howard Zinn and Robert Birnbaum, from Identity Theory:
HZ: I am waiting for somebody to write a book about the American Revolution questioning the justice of the American Revolution. In another words, asking, "Was this really a justified war?" There are there holy wars in American History—the Revolutionary, the Civil War and World War II. People are willing to say that the Mexican War was imperialist—It seems like there are (at least) two different issues here. One is the counterhistorical: how and under what conditions could these problems have been resolved differently? Let's add the assumption that under "differently," we're only concerned with "peacefully." That would be worth exploring and costing out.
RB: Now they are.
HZ: That's right. And the Spanish American War and Vietnam. But there are holy wars. Untouchable, you know. Ken Burns does the Civil War and then he does the WWII.
RB: Called it The War.
HZ: And there is nothing revisionist about that. I think it is worth questioning the justice of those wars. It’s a complicated moral issue. You might say Vietnam is easy. Iraq is easy. And the Mexican War is easy. And there are no wars which are more morally complicated. But the fact that there are morally complicated wars shouldn’t stop us from examining them. And the American Revolution, in terms of casualties, the bloodiest of wars. A lot of people don’t recognize that. There were only three million people in the colonies at that time. I’ll put it another way. It ranks with the Civil War as—
RB: Percentage of casualties against the total population.
HZ: Yes, and the question is as questions in all of these holy wars: Could the same objective have been accomplished, independence from England, ending slavery, defeating Fascism—could those have been accomplished at less than the bloody toll that was taken and without corrupting the moral values of the victors in the war? And with better outcomes? Those are questions worth asking. The American Revolution won independence from England at the expense of the Indians, at the expense of the Native Americans. What it did, the English had set a line, the Proclamation of 1763, you couldn’t go beyond it, into Indian territory. They didn’t want trouble with the Indians. Independence from England takes place, the Proclamation of 1763 is wiped out. The settlers are free to move into Indian territory. Black People—most of them joined the British side rather than the American side. It was not a revolution for them. And the question I haven’t seen asked... Canada won its independence from England without a bloody war... Conceivable? It’s like asking the question about the nature of the Civil War. Slavery was abolished in all of the countries of Latin America by 1833. Without a bloody civil war. Now, of course, all those situations are different. And complicated. All that I am saying is that I think there are questions about history that so far have been untouched and untouchable and should at least be opened up.
The other is the issue of judgment. Let's suppose that we find some plausible scenarios that solve the first question. Does that then imply that we can fault the moral judgment that led to those wars? And if so, whose moral judgment? In the case of the Revolutionary War, should the British or American colonists be held responsible, or both? Should particular leaders? Ditto the U.S. Civil War, with the North and the South, Lincoln and Davis and generals. You would also have to look at conditions leading up to the crisis: it's quite possible that the blame for the Civil War (as Zinn himself suggests) lies with the decisions made during and immediately after the American Revolution.
Also, clearly the interests of the opposed parties are not the same. If your question, say, regarding the Civil War is whether we could have eliminated slavery without a bloody and costly war, then that paradoxically seems to place the "blame" for the war solely on one part of one side, since not everyone fighting for Union sought to achieve that cause, while virtually everyone fighting for the Confederacy sought to prevent that achievement. Essentially you've precluded the question of whether the goals of the Confederacy could have been achieved without war, even if you stipulate that at some point, slavery needs to be abolished.
To me, it seems like throwing moral blame around is generally a much dicier proposition than Zinn thinks. What you really need is some argument that, not to borrow too much from game theory, presents an alternate equilibrium, where both sides could have achieved 1) what they wanted or at least 2) what was best for them if they had both pursued a different strategy.
For example, let's suppose that the U.S., Europe, Russia, and China had agreed to pursue regime change by negotiating with Saddam Hussein to step down as head of state in Iraq and to leave the country. He's allowed to go into exile in, I don't know, Egypt, with a good sum of money, his sons, and assurances that he won't be prosecuted for war crimes or crimes against humanity. That certainly would have been better for Saddam, almost definitely would have been better for Iraq, and arguably would have allowed us to achieve our objectives in Iraq and the Middle East by overseeing a stable transfer of power and slow but certain democratization.
As it was, we left Saddam nowhere to go but into hiding, the Sunnis nothing to do but to violently oppose the occupation, and the Shiites no friends but Iran. That's a bad equilibrium for everyone, but a natural one given the way the choices were presented.