The Islamic State is not a familiar terrorist threat in the way in which Americans have come to understand Islamic fundamentalist terrorism in the post-9/11 world. That does not mean that this group does not intend, and may successfully execute, conventional terrorist attacks against Western targets – they would like nothing more. But this group’s sophistication, its reach, its ability to self-finance, to recruit, and to endure are “beyond anything that we’ve seen,” according to Defense Sec. Chuck Hagel.

“They’re beyond just a terrorist group,” he told reporters on Thursday. The top Pentagon official warned that the Islamic State represents “an imminent threat to every interest we have.”

Strong language; words which have meaning and which demand action. Not only is ISIS’s very existence a threat to human dignity and the shared heritage of mankind, but it is a direct and pressing threat to U.S. national security interests. They must be stopped.

The public and this administration are, however, understandably concerned about the prospect of another ground war in Iraq. An American people, snake bit after a decade of war, do not welcome the prospect of reliving that experience. The public’s resistance to returning to Iraq has, however, begun to break down amid the rise of this threat to humanity.

When President Barack Obama announced his belated decision to mount U.S. airstrikes in Iraq, he did so with the support of bipartisan majorities. “There were no demonstrations in protest,” observed conservative columnist Peggy Noonan. “Even the pope didn’t protest.”

She noted that Americans continue to fear a new occupation and rightfully so, but the mission here is not a return to the Iraq War of 2003 – 2010. This is going to be something quite different: a purely military mission to throttle the nascent Islamic State power in its crib.

We tell ourselves that we do not want to go back to Iraq, and we don’t—all the polls show this. But facing up to what ISIS is and what it plans to do is not returning to Iraq in that we are not talking about nation-building, quixotic exercises in democracy-bringing, or underwriting governments ruled by incompetents. We are talking about other things.

“Continue bombing ISIS where potentially efficacious, as heavily and for as long as needed,” she added. “This week’s bombing forced them to give up the dam they’d seized at Mosul, an act that left ISIS looking, for the first time in its history, reduced and stoppable.”

She adds that Obama should also seek congressional authorization for continued action in Iraq, which would force him to speak honestly and openly about the scope of America’s present involvement in that country. Up to now, the White House has been insulting the public by using coded language to hide the scale of the U.S. military’s present level of engagement in the Middle East.

Syndicated columnist Charles Krauthammer observed that Obama’s rationale for continued strikes in Iraq — the protection of American assets in Baghdad and Erbil — were undone when American airstrikes began to target ISIS positions around the strategically vital Mosul dam. The administration’s claim was that it was protecting American personnel in Baghdad because, if the dam was breached, they may be threatened.

“Quite a reach,” Krauthammer noted. “An air war to prevent flooding at an embassy 200 miles downstream? Well yes, but why not say the real reason? Everyone knows it: The dam is a priceless strategic asset, possession of which alters the balance of power in this war.”

“And why not state the real objective of the U.S. air campaign?” he asked. “Stopping, containing, degrading the Islamic State.”

The Islamic State is overstretched. It’s a thin force of perhaps 15,000 trying to control a territory four times the size of Israel. Its supply lines are not just extended but exposed and highly vulnerable to air power.

The mission Krauthammer describes does not appear to require a significant American ground force, though it would be one which would only be effective in Iraq. The Islamic State’s stronghold in Syria will require an entirely different strategy, one far more robust and which may require putting American service personnel in harm’s way. But rolling back the Islamic State in Iraq is an acceptable short-term goal, and the American people should be informed that this is the mission in which their military is presently engaged.

Those opposed to going to war to rid the world of ISIS worry that achieving that objective will require more commitment than most are willing to admit. And it is possible that the American national interests at stake in this region, while appreciable, are not threatened to the degree that would merit a return of tens of thousands of American troops to Iraq. At least, not yet.

These are worthwhile debates to have, and Americans need to have an honest discussion about this threat. It is a discussion that must be led by their president. It seems, however, that some conservatives are beginning to observe that those who object to a military solution to the Islamic State threat rest their argument on the claim that it heralds a new occupation of Iraq. This is a straw man argument. The vast majority of Americans of every political stripe do not want to reoccupy that country, and this is not on the table. Destroying ISIS, however, is.

The last decade has demonstrated that the American military is not especially good at nation-building. They are, however, exceptional at getting at and destroying the enemy. Fortunately for them, all that would be asked of them this time is the latter.