Opinion | Who Is Blowing Up Russia?

There are two plausible hypotheses regarding Friday’s terrorist attack at a concert hall outside Moscow, in which at least 139 people were killed. The first is that it was an inside job — orchestrated by Russian security services, or at least carried out with their foreknowledge.

The second is that it wasn’t.

In open societies, conspiracy theories are for cranks. In closed societies, they’re a reasonable (if not always correct) way to understand political phenomena.

In 1999, more than 300 Russians were killed and 1,700 injured in a series of apartment bombings for which authorities blamed Chechen terrorists. The bombings served as a pretext for Vladimir Putin — who had ascended swiftly from secondary apparatchik to director of the Federal Security Service, or F.S.B., to prime minister — to launch the second Chechen war.

Then something strange happened. The police found three enormous sacks of white powder in the basement of an apartment building in the city of Ryazan, connected to a detonator and timer set to go off at 5:30 in the morning. Initial tests of the powder found it contained the same explosive, hexogen, that had been used in other bombings.

The police soon apprehended the culprits who had placed the sacks — and they turned out to be employees of the F.S.B. The Russian government later said the sacks were filled with sugar and had been left in the buildings as a training exercise. But as the historian David Satter and others have documented, the claim borders on the preposterous. And numerous journalists and politicians who sought to investigate the incident wound up poisoned or shot dead.

Why does this history matter? Because it shows that Putin “has no allergy to blood, Russian or any other kind, if spilling it furthers his goals,” as Garry Kasparov noted in The Wall Street Journal.

It says something that Putin seemed to provide a motivation for a false-flag attack by almost immediately pointing the finger at Ukraine for Friday’s massacre — an absurd if telling choice of a culprit, given that Russia would immediately destroy its credibility with its Western partners if it had any connection to the event.

It says something, too, that the attack occurred right after Putin’s re-election in this month’s sham vote, and just as he is seeking to mobilize tens of thousands of fresh troops for the war in Ukraine. What better way for him to do so than to revert to the tried-and-true formula of creating panic on the home front so that he can bring destruction to the frontier?

That’s the first hypothesis. But there’s also a brutal history of Islamist terrorism in Russia, and the United States alerted Moscow on March 7 (just as it alerted Iran before an ISIS attack there in January) that an attack was imminent. In both cases, the warnings were ignored — Putin dismissed it as “an attempt to frighten and destabilize our society” — perhaps because cynical regimes have trouble imagining the possibility of altruistic motives.

This suggests what we already knew: Putin’s state is as incompetent as it is brutish. And with the enemies it has, it doesn’t need to invent a fictitious conspiracy between Western powers and the “Nazi regime” in Kyiv. Russia will never resolve its inner weaknesses — a shrinking population, fissiparous ethnic minorities, a brain drain and an energy-dependent economy — through foreign conquests.

But it suggests something else: Five years after the Islamic State’s so-called caliphate fell in northern Iraq and Syria, ISIS and its offshoots are far from gone.

Around 9,000 hardened ISIS fighters are held as prisoners in several camps in Syria, guarded by Kurdish forces with American help (which Donald Trump attempted to end). The branch of ISIS accused of the Moscow attacks, known as ISIS-K, is estimated to have as many as 6,000 fighters at large, mostly in Afghanistan. Other ISIS affiliates operate throughout Africa, where U.S. counterterrorist efforts are being hampered by local upheavals.

In other words, as Washington has retreated from (or been forced out of) its efforts to confront global disorder, the disorder has grown. What happened in Moscow is reminiscent of what happened at the Bataclan theater in Paris in 2015, where 90 were murdered. ISIS seems to have a taste for concert halls.

The word “pivot” gets used a lot in foreign policy discussions, as in the Obama administration’s “pivot to Asia” or the “pivot to great-power competition” under Trump and President Biden. But if the lesson of the first pivot is that we neglected NATO and European security at our peril, the lesson of the second is that we have lulled ourselves into the belief that our Islamist terror problem is largely behind us. As Israel found out on Oct. 7, a country’s mortal enemies aren’t tamed or vanquished just because leaders have other priorities.

The American security challenge today is global: a resurgent ISIS, a revanchist China, a regionally aggressive Iran and a Russia where the lines between grandiosity and paranoia blur. Whether what happened in Russia was Islamist terror, an F.S.B. conspiracy, or some appalling combination of both, it augurs ill for us.