Jihadist terrorist activities in Europe, which far outnumber those in the United States, are now mostly run by independent local groups, though the more serious plots appear to have connections to groups in North Africa or the Middle East, according to a new Rand Corp. study.

The study, conducted for the Pentagon, was released last week.

While Americans generally just think of jihadist terrorists as threatening the United States, “On average . . . European authorities arrest some 200 individuals and thwart a handful of plots of jihadist inspiration every year,” according to the study entitled “Radicalization, Linkage and Diversity, Current Trends in Terrorism in Europe.”

Al Qaeda recruitment in Europe, which was never great, has all but vanished.

“Some mosques still play an important role in the radicalization process and in the formation of spontaneous clusters of like-minded individuals. However, most of the activities that normally follow such initial steps no longer take place in mosques but are instead conducted in small private circles outside of the mosques,” the study says.

“Scores of European jihadists have indeed received their first exposure to jihadist ideology in front of a computer, in a jail cell, or by interacting with members of nonviolent Islamist organizations,” it says.

There are cases of radical preachers and those who have fought in various places working to radicalize Europeans, but they are fewer since the police and security force crackdowns after Sept. 11, 2001. “Arrests were particularly numerous in Europe, where authorities often moved against networks they had been monitoring for years,” according to the study.

As for “Inspire,” the slick English-language magazine begun in 2010 by Yemen-based Al Qaeda in the Arabian Peninsula, it is more valued for its propaganda than for “any major operational impact it might have,” the study found.

Recent events in Europe have increasingly motivated European jihadists — who more and more are second-generation Muslims — and their local sympathizers. “As homegrown networks began planning attacks in several countries, Europe shifted from occasional to freqent terrorist target,” the study says. It also found that because there was little contact with al Qaeda or individuals who had trained at its main affiliates, “most of the attack attempts were amateurish.”

Of 30 jihadist terrorist plots in Europe between 2006 and 2010 examined in the study, 10 were considered “serious.” Of those, five were undertaken independent of al Qaeda or affiliates. In three of those five, the explosives failed to operate properly. In four of the five classified “hybrid,” with some tangential connection “no attack materialized because authorities arrested the cell members during the preparation stage,” according to the study. In those four cases, one or more of the cell members involved had received bomb training in Pakistan.

The study says that “dozens of German jihad enthusiasts” travel to Pakistan to train with a splinter group of Uzbekistan Islamic jihadists who have camps in the tribal areas of that country. Second-generation Somalis, many from Sweden, are returning to that country for training. So are a few from the United States.

Experienced Europeans these days consider it more useful to keep known jihadists “on the street,” monitoring their activities to see their contacts and gain insights into their networks. “This policy has led to some remarkable successes but is also highly risky, as there is always the possibility that authorities might not be able to monitor all activities,” the study says.

An added value of the Rand study is its presentation of history. While Sept. 11 was a wake-up call in the United States, the study reminds us that Europeans have spent decades confronting terrorists, foreign and domestic. InEngland it was the Irish Republican Army; in Italy, the Red Brigades; and in Germany, the Baader Meinhof Gang.

In the early 1990s new groups arose as several hundred Islamic veterans who had fought in Afghanistan against the Soviets took political asylum in European countries. They formed jihadist militant cells to propagandize, recruit and raise money with the aim of overthrowing secular leaders in their home countries, according to the study.

“Algerian, Egyptian and Tunisian networks . . . were organized,” the study says. Though the networks sent militants to the Middle East or South Asia for training and fighting, they “showed no violent intent” to their European host countries, which they viewed as convenient bases of operations, the study says.

As Osama bin Laden grew al Qaeda’s Afghan training camps in the late 1990s, a new phase began. European networks “with varying degrees of allegiance” fell in line with his fight against secular Muslim regimes and their Western supporters. The study recalls bin Laden’s purpose in attacking the United States was to end Washington’s support of Muslim secular regimes by “making a continued American presence in the Middle East too painful to bear.”

It is worth remembering, as the study puts it, while al Qaeda had a small presence in Europe, “because of their familiarity with the West, Europe-based militants led two of the first operations planned by the jihadist movement against the American homeland,” the failed Millennium bombing of the Los Angeles Airport in 2000 and Sept. 11.