Hanover, N.H. — SURVEYING the aftermath of the terror attacks in Paris, most Americans probably feel despair, and a presentiment that it is only a matter of time before something similar happens here. Even as Americans have felt the pain of the French, they have worried, not surprisingly, considering 9/11, about whether their country is next.

But such anxiety is unwarranted. In fact, it’s a mistake to assume that America’s security from terrorism at home is comparable to Europe’s. For many reasons, the United States is a significantly safer place. While vigilance remains essential, no one should panic.

The slaughter in France depended on four things: easy access to Paris, European citizens happy to massacre their compatriots, a Euro-jihadist infrastructure to supply weapons and security agencies that lacked resources to monitor the individuals involved. These are problems the United States does not have — at least not nearly to the degree that Europe does, undermining its ability to defend itself.

American policy makers have eyed Europe’s external border controls skeptically for many years: The Schengen rules, which allow for free border-crossing inside most of the European Union, have made life simple for criminals.

Complicating matters is the ease with which a terrorist might slip out of Syria, cross through Turkey and enter Greece and the European Union, as at least one of the Paris killers appears to have done. Counterterrorism often boils down to a search for a few individuals, and the chaos surrounding the flood of refugees — a record 218,000 entered the European Union just last month — has exacerbated the difficulty of keeping track of such incoming security threats.

But the United States doesn’t have this problem. Pretty much anyone coming to the United States from Middle Eastern war zones or the radical underground of Europe would need to come by plane, and, since 9/11, we have made it tough for such people to fly to the United States.

And it helps that America’s two immediate neighbors, Mexico and Canada, have extremely cooperative security authorities, which prevents would-be terrorists from slipping across our land borders.

Then there’s the domestic challenge. It appears the Paris attacks involved both Middle Eastern operatives and Muslims from France and Belgium. But some high-profile exceptions aside, American Muslims are much less attracted to the Islamic State and its ideology than European Muslims seem to be. Americans have traveled to ISIS-controlled territories at a rate of roughly a third that of their European Union coreligionists.

Yes, some of the worst attacks of recent years here at home have been by deeply alienated Muslims, including Nidal Hasan, the Fort Hood shooter, and the Tsarnaev brothers, perpetrators of the Boston Marathon bombing. But the incidence of such malcontents is lower than in Europe, whose larger Muslim communities, social science data shows, are markedly less integrated.

Although European governments have been working to ameliorate grievances, European Muslims remain poorer, more ghettoized and more discriminated against than American Muslims, whose levels of education and income mirror those of the entire American population.

We should be thankful for the paucity of American extremists, given our superabundance of weapons. The Islamic State’s innovation over its predecessors from Al Qaeda, who relished the drama of bomb strikes, is indiscriminate attacks with firearms. Many of the guns are from government stocks in places like Libya and Syria, which has changed the equation in formerly gun-free Europe.

The United States has another advantage: an intelligence, law enforcement and border-control apparatus that has been vastly improved since the cataclysm of 9/11. Post-9/11 visa requirements and no-fly lists weed out most bad actors, and both the Bush and Obama administrations demanded that countries in our visa waiver program provide data on extremists through information-sharing pacts called HSPD-6 agreements. Improvements continue, like an advance passenger information/passenger name recognition agreement with the European Union of 2012.

In fact, America has spent more than $650 billion since 9/11 on homeland security, or around $47 billion a year. In contrast, after the Charlie Hebdo killings, France announced a multiyear $786 million effort to combat terrorism. The annual budget for Germany’s entire intelligence service is $660 million. The resulting gaps in France’s counterterror regime are self-evident: Already, there are indications that the Paris crew operated undetected because of surveillance shortcomings, as was true with the Charlie Hebdo attacks.

None of this should lead American authorities, or the American people, to settle into a false sense of security. The foremost task for the years ahead is to double down on our intelligence collection and press our European partners to dramatically expand theirs.

If anything, what the Paris attacks show is that the world needs America’s intelligence and security resources even more than its military might. The American intelligence community is the indispensable hub of global counterterrorism efforts, but the large numbers and geographic spread of the Islamic State mean that the United States must commit even more resources. Europe must step up and help build the basis for a deeper, more far-reaching collaboration.

Europe, already disadvantaged by geography, has to try a lot harder. It’s a daunting but not insurmountable challenge, and America must be ready to help, for Europe’s sake and its own.