With President Obama using his address at the United Nations General Assembly to rally more support for the U.S.-led military campaign against the Islamic State in Iraq and al-Sham, or ISIS, there are at least two ways to view what is happening.

One is that the President is merely doing what is necessary to address a serious threat to American interests and to the security of American citizens. If we don’t deal with ISIS (also known as ISIL, or I.S.) now, this argument goes, we’ll have to deal with it later, when it may have become bigger and even more deadly. The territorial gains of the jihadi army represent an immediate threat to U.S. allies in Iraq; a medium-term threat to regional U.S. allies, such as Saudi Arabia and Israel; and a long-term threat to the U.S. mainland, through the export of terrorism. The longer the U.S. allows ISIS to taunt it, beheading its citizens and seizing weapons it provided to the Iraqi government, the bigger the damage to American credibility and power will be.

“ISIL has global aspirations and, as President Obama has made clear, ISIL’s leaders have threatened America and our allies,” Chuck Hagel, the Defense Secretary, told Congress last week. “If left unchecked, ISIL will directly threaten our homeland and our allies.” And here’s Obama today at the U.N.: “The only language understood by killers like this is the language of force. So the United States of America will work with a broad coalition to dismantle this network of death.”

That’s the official reading. An alternative interpretation is that Obama may well believe everything he says about the dangers ISIS presents, but he’s also acting politically in the run-up to the midterms. Having spent much of his tenure resisting calls for military interventions and articulating a cautious realism about America’s power to dictate events in the Middle East and elsewhere, he has thrown up his hands and given in to the war party.

Versions of this view are percolating on the left and the right. In a piece at the Washington Post, Katrina vanden Heuvel, the editor of The Nation, accused Obama of “surrendering to three forces”: a media “lathered into war fever,” a group of liberal interventionists in his own party, and “the mindless bellicosity of his opposition.” Andrew Sullivan, despairing of a President he has for the most part vigorously supported, writes, “He has folded—and you can see he knows it by the wan, listless look on his face. His presidency may well now be consumed by this new war and be judged by it—just like his predecessor’s. And all because when Americans are faced with even the slightest possibility of future terror, they shit their pants and run to daddy.”

Only Obama knows for sure what his real motivations are. In all probability, he sincerely believes that the attack on ISIS is consistent with the principles he has espoused all along. As he pointed out in his 2009 Nobel Prize speech, he is not a pacifist but a skeptic. He believes that some wars are just and justified. “I face the world as it is, and cannot stand idle in the face of threats to the American people,” he said in Stockholm. “For make no mistake: Evil does exist in the world.… To say that force may sometimes be necessary is not a call to cynicism — it is a recognition of history; the imperfections of man and the limits of reason.”

Few would argue with the idea that ISIS is an evil organization. It preaches sectarianism and hatred; it massacres its opponents and chops up their bodies; it beheads prisoners; it oppresses women; since the U.S. air raids have begun, it has called on its supporters overseas to carry out terrorist attacks. “The world must know that the United States of America will never back down in the face of such evil,” Obama said in Edgartown last month, the day after somebody from ISIS uploaded a video of James Foley, an American journalist, being executed.

On the other hand, there is a lot of evil in the world. If the United States were to confront it always and everywhere with military action, it would permanently be at war. Moreover, General Martin Dempsey, the chairman of the Joint Chiefs of Staff, has said that ISIS doesn’t represent an immediate threat to the United States. Rather than pledge to destroy it, a commitment that made large-scale U.S. military action inevitable, why didn’t Obama take the more cautious approach of containing ISIS inside Iraq, beefing up its opponents, and waiting for it to collapse? (In an excellent piece in Wednesday’s Times, David Motadel, a historian at the University of Cambridge, points out that Islamic “caliphates” are neither new nor stable.)

Here is where Obama’s critics may be onto something. It’s not that the President is “playing” at politics, or mendaciously trying to whip up a little war to rescue the Democrats in November. It’s a deeper issue than that.

All politicians respond to political incentives—even ones who, like Obama, sometimes try to hold themselves above the fray. In a situation like the one the President has faced over the past month, the incentives point in mostly one direction: toward a “bombs away” strategy. Giving into the calls for action and unleashing America’s mighty military is, by far, the easiest thing to do. To act cautiously, take the long-term view, and try to educate the public about the limits of American power—that is much harder and riskier.

The problem isn’t just the presence in Washington of a war party that is constantly seeking to portray the President as weak and ineffectual, or a military-industrial complex that stands to gain from a lengthy bombing campaign. These things exist, but they are just two components of an ecosystem that favors certain outcomes. It’s almost like a war machine.

The media, of course, is another component—an important if unwitting one. When something like the downing of the Malaysian airliner or the release of the James Foley video happens, and the media switches on its magnification glass, sanity, let alone perspective, is difficult to maintain. For governments or individuals at the center of such frenzy, about the only hope is that something else will happen to change the story. In this case, though, that possibility had already been removed. With ISIS holding more American captives, it was only a matter of time before more grisly videos would be released. At the White House, that must have been a factor weighing on the President.

And so, surely, was public anger. On September 9th, a week after the release of a video showing the beheading of a second American journalist in Syria, Steven Sotloff, an NBC News/Wall Street Journal poll indicated that a majority of Americans favored a stronger military response. An ABC News/Washington Post poll found the same thing: seventy-one per cent of respondents said that they favored bombing ISIS targets inside Syria. So much for war-weariness and isolationism. In the words of the Journal, there had been “a remarkable mood swing for an electorate that just a year ago recoiled at Mr. Obama’s proposal to launch airstrikes against Syria.”