In a grim coincidence of history, Operation Odyssey Dawn, the UN-approved but American-led military campaign to establish a no-fly zone over Libya, began on March 19, exactly eight years after George W. Bush began his “shock and awe” war against Iraq.

There are many lessons to be learned from the debacle in Iraq, but one of the most important is that it was a blatant violation of international law, an unjustified, unprovoked war of aggression. The Iraqi people have paid a tragic price for the Bush administration’s disregard of global opinion, and America’s reputation was deeply tarnished. Indeed, President Obama was elected in 2008 in part to restore the country’s moral standing in the world.

In many respects, Obama seems to have learned this lesson. He resisted calls from right and left for unilateral US intervention in Libya. Instead, the White House favored a series of UN Security Council–mandated measures to weaken Muammar el-Qaddafi’s hold on power and prevent him from slaughtering his own people. It wasn’t until it was clear that those actions would fail—and the potential for a massacre of civilians had increased—that the administration began to consider military action.

Moreover, the president did what Bush did not do in 2003: he insisted there would be no US military action without Security Council approval and regional involvement, in particular from members of the Arab League. Obama also took steps to try to limit America’s military footprint and ruled out sending ground troops into Libya—indeed, the Security Council resolution explicitly forbids foreign occupation forces. The resolution also makes clear that its goal is the protection of civilians rather than regime change. Thus, the administration’s decision to support the UN action is an important defense of a multipolar world that operates according to international law.

But there is a second set of lessons from the Iraq War, relating to the costs and benefits of military action, that should raise serious concerns about the White House’s decision. First, like the Iraq War, the Libya intervention is a war of choice, undertaken by an executive acting without Congressional authorization. This is a continuation of a dangerous—and unconstitutional—precedent, one that President Obama himself opposed when he was a senator. “The president does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation,” Obama said in December 2007.

Furthermore, as we should have learned from the Iraq War, the use of military force can have all kinds of unintended consequences. We may be going to war to prevent civilian casualties, but even the most prudent use of air power is incapable of doing that. The likelihood of US or coalition forces killing civilians will only increase if Qaddafi’s troops solidify their hold on Tripoli and other cities; urban warfare is notoriously messy. The UN resolution forbids foreign occupation, so what will we do if Qaddafi hangs on and the conflict settles into a grinding civil war, with all its attendant chaos and bloodshed? Mission creep seems to be an inevitable feature of this kind of intervention.

The dilemmas abound. The UN resolution calls for a cease-fire; yet rebel forces insist they will not observe it, even if Qaddafi decides to. Does this mean allied forces will be obliged to attack the rebels? The resolution also calls for an arms embargo, without excluding the opposition from that stipulation. And yet leaders and pundits among the allies are talking about supplying arms to them. The resolution does not mention regime change, and yet that is the Obama administration’s policy; how will the administration square White House policy with its UN obligations?

Perhaps most troubling of all is the flagrant hypocrisy of US pursuit of yet another Middle East military campaign, ostensibly with humanitarian goals, even as it gives weapons and diplomatic support to the corrupt royal families of Bahrain, Saudi Arabia and the other tin-pot tyrants of the Persian Gulf, who have banded together in savage repression of their own democratic oppositions. Consistency—never a notable virtue of US Mideast policy—would seem to demand, at the very least, an end to the Gulf arms pipeline, and diplomatic support for the people of Bahrain against the thugs of the Gulf Cooperation Council.

Military “solutions” to grave humanitarian crises are tempting, but history shows that they rarely solve anything. They usually lead to more problems, deeper tragedy. Given our massive budget deficits and bloated Pentagon spending (see Robert Dreyfuss, in this issue), never has there been a better time for America to end its role as global policeman in favor of diplomatic and economic multilateralism.