The United States can no longer afford to “react to threats after they have emerged,” argues Emily Estelle in a new report on the dangers posed by the violent strains of Salafism, the fundamentalist Islamic ideology espoused by Islamic State. Noting the growing power vacuum in the Middle East and the pressing challenges posed by Russia and China, Estelle outlines a path for the U.S. to “avert rather than mitigate [the] risk” of global Salafi-jihadist terror. Failure to do so, she contends, will exacerbate domestic tensions while accelerating wide-ranging threats to national security.

A new jihadist wave is the last thing Western policymakers want to recognize or prepare for. But Americans face a more serious terror threat than they realize. The global Salafi-jihadist movement, led by al-Qaeda and Islamic State, has not faded into irrelevancy but has grown greatly in manpower, wealth, capability, and geographical extent and is stronger by some measures than it has ever been.

The movement’s flashiest endeavors—spectacular terror attacks and a border-crossing caliphate—are in a lull that the largely temporary effects of counterterrorism pressure only partly explain. Deliberate adaptation is also at play; Salafi-jihadist leaders have learned to eschew direct attacks on the U.S. and European homelands, on the whole, to avoid drawing attention to their successes in putting down deep roots in many countries. But they have not given up their aim—toppling and replacing states across the Muslim world—or their willingness to use terror attacks to achieve their ends.

Over the past two decades, the U.S. government has disaggregated threats and sought to manage them sequentially: small or lone-wolf attacks in the United States; resurgent Salafi-jihadist groups across Africa, the Middle East, and South Asia; government collapse in these regions; and mass-migration refugee crises driven by conflict and climate change. These problems range from manageable to inconsequential in the establishment worldview. But this approach fails to recognize the cumulative weight of these interconnected developments and the major threat they represent in combination.

This week, there have been numerous unconfirmed reports about the fate of Esmail Qaani, who is the head of the Quds Force, the expeditionary arm of Iran’s Revolutionary Guards. Benny Avni writes:

On Thursday, Sky News Arabic reported that Mr. Qaani was rushed to a hospital after suffering a heart attack. He became [the Quds Force] commander in 2020, after an American drone strike killed his predecessor, Qassem Suleimani. The unit oversees the Islamic Republic’s various Mideast proxies, as well as the exporting of the Iranian revolution to the region and beyond.

The Sky News report attempts to put to rest earlier claims that Mr. Qaani was killed at Beirut. It follows several reports asserting he has been arrested and interrogated at Tehran over suspicion that he, or a top lieutenant, leaked information to Israel. Five days ago, the Arabic-language al-Arabiya network reported that Mr. Qaani “is under surveillance and isolation, following the Israeli assassinations of prominent Iranian leaders.”

Iranians are desperately scrambling to plug possible leaks that gave Israel precise intelligence to conduct pinpoint strikes against Hizballah commanders. . . . “I find it hard to believe that Qaani was compromised,” an Iran watcher at Tel Aviv University’s Institute for National Security Studies, Beni Sabti, tells the Sun. Perhaps one or more of [Qaani’s] top aides have been recruited by Israel, he says, adding that “psychological warfare” could well be stoking the rumor mill.

If so, prominent Iranians seem to be exacerbating the internal turmoil by alleging that the country’s security apparatus has been infiltrated.