THE UNITED STATES has long faced threats from a lethal brand of terrorism that perverts one of world’s great religions. We have been relentless in targeting Al Qaeda and its affiliates, but the Islamic State, also known as ISIS or ISIL, now poses a profound and unique threat to the entire world.

What we are confronting is nothing less than a violent extremist enterprise. It has employed violence, intimidation, and genocidal brutality to impose its will across large swaths of Syria and Iraq. The Islamic State controls more territory than Al Qaeda ever has, which means it has access to money on an unprecedented scale to finance its mayhem.

With American leadership, the world is responding with a unity that shows these criminals that we will not allow them to divide us or force their nihilistic vision on helpless people, regardless of ethnicity, religion, or nationality. On Wednesday, the United Nations Security Council unanimously passed a resolution condemning the gross abuses carried out by the Islamic State in Syria and Iraq.

There is a vigorous international debate under way about what it means to destroy the Islamic State, about how effective and resilient the growing coalition will be, and about how the strategy will unfold in the coming months.

Here at home, I understand why Americans are weary about US involvement in the volatile Middle East. People are right to ask tough questions, and we have a responsibility to answer them.

I am proud to work for a president who asks questions before using military force because, after all, I remember the words of the conservative Edmund Burke: “a conscientious man would be careful how he deals in blood.”

So let’s be clear about we’re doing — and what we’re not doing.

This is not the prelude to another US ground war in the Middle East. President Obama has said repeatedly that US ground troops will not engage in combat roles. He means it. I volunteered to serve and fought in a war I came to believe was a mistake. I take that lesson seriously. This will not be another one of those interventions.

Finally, this campaign is not about helping President Bashar Assad of Syria. We are not on the same side as Assad — in fact, he is a magnet that has drawn foreign fighters from dozens of countries to Syria. As the president has said, Assad lost legitimacy a long time ago. We are embarking on an important effort to train and equip vetted members of Syria’s opposition who are fighting the Islamic State and the regime at the same time. By degrading the Islamic State and providing training and arms to the moderates, we will promote conditions that can lead to a negotiated settlement that ends this conflict.

So how do the United States and the more than 60 countries that have joined the effort so far succeed? Military action is a key component of the campaign. The Islamic State rules at the barrel of a gun and the blade of a knife, and that’s the only language its adherents seem to understand. But as the president said, America is not in this fight alone. Iraqi and Kurdish troops are fighting on the ground now, and over the months the moderates in Syria will become a more effective force as we provide training, equipment, and military advice.

But our strategy is broader. One important step is reducing the number of foreign fighters flocking to the black flag of the Islamic State. These foreigners, including many from the United States, pose an immediate danger on the battlefield and a longer-term threat if they are allowed to return to their home countries. So every country must detect and disrupt the recruitment by the Islamic State, because keeping fighters from making it to the war is more effective than taking them out after they arrive. And every country must increase its vigilance in monitoring those who return from the battlefield.

We must work to strangle the Islamic State’s funding. The Islamic State has reaped millions of dollars from its sales of pirated oil, extortion rackets, and illegal taxes on businesses in the territory it controls. Ending its taxes and extortion will require winning back territory, but the world can act now to dry up the black market for the oil the Islamic State is smuggling across parts of Iraq, Syria, Turkey, and Iran. The illicit oil provides a large share of the Islamic State’s financing for its terror and there are forceful steps we can take to disrupt it.

The evil that the Islamic State represents is not something that Iraq or the region can take on alone. We face a common threat and it requires a common response. Acting together, with clear objectives and strong will, we can protect the innocent, contain the danger, and demonstrate that our ideals are more powerful than those who seek to impose their warped beliefs at the point of a gun. The Islamic State is odious, but it is far from omnipotent — it will be defeated.

 

THE BOSTON GLOBE