Faced with an imminent genocide in Iraq, doing nothing would have been morally indefensible.
So the limited, humanitarian mission that President Barack Obama launched Friday, including airstrikes targeting powerful radical Islamist forces in northern Iraq, was the right thing to do.
Multiple airstrikes using predator drones and laser-guided 500-pound bombs that cleared the way for airdrops of food and water to people trapped on a barren mountain were met with international support. So was the plan to carve out a corridor they need to travel safely and into neighboring Turkey.
Obama's stated objectives are twofold. The first is to protect American diplomats, military advisers and civilians at the U.S. consulate in Irbil, the capital and largest city in the Kurdistan region. The second is to prevent the slaughter of 40,000 Christians and Yazidis, members of an ancient religious sect, surrounded on Mount Sinjar about 120 miles west of Irbil. They had fled to the mountain with little more than the clothes on their backs.
The Islamic State group, which now controls about a third of Iraq and a large swath in Syria, has given those religious minorities a chilling ultimatum: Convert to Islam or die.
These fanatical thugs who embrace martyrdom committed mass executions as they advanced into Iraq, so there was little doubt they meant what they said.
For humanitarian reasons, Obama was forced to reverse his policy, which has been all about getting out of Iraq, but that raises the specter of being drawn back into a place the American public doesn't want to go.
So, what's the long-term strategy in Iraq, a nation bombed by four successive U.S. presidents?
An eight-year war, an elected government and billions of U.S. dollars spent training and equipping the Iraqi army didn't bring stability to that troubled country. So there's little reason to believe anything the United States can do now will end the bitter regional and religious conflicts threatening to cleave Iraq into several autonomous regions.
Alliances are so tangled in Iraq and the Middle East that the radical Islamic State group the U.S. military is bombing -- previously known as ISIS -- includes some of the rebels we've armed in Syria, where they are fighting to oust dictator Bashar Assad. There is good reason to resist dipping a toe back into a quagmire that has already cost the United States so much in a place where it's so hard to tell friend from foe.
But the Islamic State group is ruthless. Its vision of an independent caliphate would become a haven for international terrorists. The group has already made threats against Norway. If the group manages to hold and govern the territory it has seized, it would further destabilize the Middle East and become a direct threat to U.S. national security.
Obama said he will not send combat troops to Iraq. He shouldn't. If the Islamic State group threatens the approximately 800 U.S. personnel and facilities, the response must be focused and limited and not a return to a ground war.
As this immediate crisis eases, Obama, preferably with the help of our allies, must work to block the Islamic State's campaign of terror. Middle East powers such as Saudi Arabia, Jordan and Iran, along with our Western allies, must coalesce behind a strategy to isolate and defang the Islamic State fighters.
Obama is still pushing for a democratically elected Iraqi government that includes Sunni, Shia and Kurdish Iraqis. That would be an ideal end to the chaos, but it's increasingly unlikely with the country split into warring factions.
We've learned that the United States shouldn't intervene militarily every time there is a crisis in the world. Even when genocide looms, our response should be informed by what we can do and at what cost.
But the Islamic State group presents a humanitarian nightmare and a virulent terrorist threat that cannot be ignored.