Air strikes by U.S. Navy aircraft on artillery sites of the so-called Islamic State, generally known as ISIS, have made it possible for up to 50,000 Yazidi refugees to find food and shelter in new safe havens. The U.S. should continue the air campaign until the humanitarian job can be completed.

A C-17 and its crew from Joint Base Charleston are among the U.S. planes that have participated in the humanitarian mission.

President Barack Obama's decision last week to authorize the air strikes, as well as the air drops of food and water, has so far succeeded in protecting the Yazidis, who face death at the hands of ISIS Sunnis.

"It was because of the planes that we could leave. They opened the way," Zaid Hassan Harmouch, 66, told The Washington Post.

He led his family from the rocky, waterless mountain where they had initially sought refuge after planes destroyed an ISIS unit blocking their path.

The air strikes by U.S. and Iraqi aircraft may also have turned the tide of battle for the Kurdish region of Iraq, allowing the Kurds to retake towns seized by the Islamic State.

News reports say the U.S. government, in a reversal of policy, has also begun to arm the Kurdish militia, known as the peshmerga. Whether this step represents a change from the U.S. view that Iraq should not be allowed to disintegrate into separate Shia, Sunni and Kurdish mini-states is unclear. But the reports say that cooperation between Iraqi and Syrian Kurds played a key role in bringing the Yazidis to safety once air attacks opened the way.

Kurds have long sought a separate nation, and the current fragmentation of Iraq may have opened a door to that objective.

Certainly, events in Baghdad, where the United States still has 5,000 American embassy personnel, leave open the possibility of the disintegration of Iraq.

On Monday, Iraqi President Fuad Masum, a Kurd, invited a rival of Iraq's Shia Premier Nouri al-Maliki to form a unity government. But Mr. al-Maliki rejected the effort to push him aside and brought military units loyal to him into the government zone of the city.

If Premier al-Maliki uses force to cling to power, a breakup of Iraq becomes much more likely. President Obama's new decision to provide military support to the Kurds may be a hedge against that possibility. So far the Kurds have offered the only effective resistance in Iraq to the spread of the Islamic State.

But Secretary of State John Kerry made it clear Monday that the United States supports President Masum and the objective of a unity government.

None of these developments suggests that it will be easy to reverse the gains made by the Islamic State any time soon, a point made by Mr. Obama on Saturday when he said that improving Iraq's security "is going to be a long-term project." The president was not prepared to "give a particular timetable" for how long the United States will continue to attack ISIS targets.

Meanwhile, Mr. Obama draws fair criticism regarding the rise of ISIS. His own former Secretary of State, Hillary Clinton, in an interview with The Atlantic magazine Sunday, blamed the president's failure to engage with more moderate rebels in Syria.

But at least President Obama is responding now, and with notable success on the humanitarian front.

And as Joint Base Charleston aptly put it in a Monday statement announcing that the locally based C-17 had made another humanitarian drop Sunday night: "We're proud of the contributions of our deployed teammates."

So are we.

As the U.S. effort in Iraq continues, President Obama should assess whether air power can be strategically applied to save Baghdad.