President Barack Obama's decision to launch air strikes against Sunni Islamic extremists in Iraq may be viewed as a justified response to protect U.S. personnel threatened by a growing terror insurgency, and also may in the short term help tens of thousands of refugees facing genocide, but our battle-weary nation has little appetite for renewing what Mr. Obama himself once called "a dumb war."

When he addressed thousands of cheering troops at Fort Bragg in North Carolina in December 2011 at the end of the Iraq war - during which nearly 4,500 U.S. soldiers died and 30,000 were wounded - Mr. Obama proclaimed, "Everything that American troops have done in Iraq, all the fighting and dying, bleeding and building, training and partnering, has led us to this moment of success. The war in Iraq will soon belong to history, and your service belongs to the ages."

Mr. Obama's characterizing the end-of-war ceremony then as a "moment of success" is reminiscent of a 2003 speech given aboard an aircraft carrier by his predecessor, President George W. Bush, beneath a banner that prematurely read, "Mission Accomplished." Fighting raged for another eight years.

Now, three years after the formal declaration of the end of the war, the militant group ISIS has been gaining strength, which prompted Mr. Obama's announcement Thursday that he had authorized renewed air strikes. That threat became reality Friday when two F-18 fighters dropped 500-pound laser-guided bombs on a mobile artillery target near Irbil.

U.S. officials say militants of the Islamic State were using the artillery unit to shell Kurdish forces near U.S. personnel, and also had pinned down refugees without food or water on Mount Sinjar in northern Iraq.

In addition to the air strikes, U.S. planes dropped supplies to these refugees, though by some reports many had fled in advance of the bombings.

Mr. Obama promised there would be "targeted air strikes" against the rebels.

How many times in U.S. history have our leaders talked about "pinpoint" air attacks while pledging in no way would there be "boots on the ground?"

How many times have we then sent in "military advisers" to train allied troops?

How many times has that been followed by "limited incursions" by "special forces?"

And how many times have we then decided to send in a small group of soldiers, and how many times have they escalated to extended deployments? The slope is extremely slippery.

The renewed air attacks come during a time of growing volatility in several other hot spots, including the Ukraine and Russia; Israel and Gaza. These tinderboxes don't need more sparks to ignite a greater conflagration.

In addition, how can the United States justify air strikes against genocidal extremists in Iraq while failing to act more decisively against despots in Syria, the Sudan and other totalitarian regimes?

Again, the strikes against ISIS may be warranted, but Mr. Obama needs to make a more cogent case to the American public.

In 2007, Mr. Obama, then a presidential candidate, nobly proclaimed, "The United States has a moral obligation anytime you see humanitarian catastrophes. When you see a genocide in Rwanda, Bosnia or in Darfur, that is a stain on all of us, that's a stain on our souls… We can't say 'never again' and then allow it to happen again, and as a president of the United States I don't intend to abandon people or turn a blind eye to slaughter."

He then went on to win not only the presidency, but the Nobel Peace Prize.

Mr. Obama wasn't the first Nobel Laureate to launch a military strike and probably won't be the last. In fairness, he inherited the Iraq War, which sadly shows no signs of having ended with a lasting peace.

We fear a similar development in Afghanistan, where the U.S. role is winding down but there is little assurance hostilities will end any time soon.

While the United States must defend itself and support its allies, Benjamin Franklin was onto something when he observed: "There was never a good war or a bad peace."