Last month, Spanish police arrested 11 Islamist extremists who were operating at 17 locations across the country’s northeastern region of Catalonia. After a year-long investigation, police detained ten men and one woman, aged 17 to 45, who were all “assumed to be implicated in diverse crimes related to jihadist terrorism, especially linked to Islamic State,” Reuters reported. Today, The Wall Street Journal confirmed those suspicions by reporting that the extremists, called the Islamic Fraternity for the Preaching of Jihad, had planned to destroy a Jewish bookstore in Barcelona:The cell, which featured prominent roles for converts to Islam, tried to recruit fighters to join Islamic State in Syria and developed plans to bomb a Jewish bookstore in Barcelona and snatch and behead a captive, according to police and prosecutors in court documents.These arrests bring the total number of persons detained in Spain so far in 2015 for suspected ties to terrorism to 42, according to Spain’s Foreign Ministry. Last year, 46 such arrests were made.The surveillance of the swelling number of terrorist operations in Spain is reflective of a larger such operation across Europe, which comes on the heels of the Charlie Hebdo attacks in Paris in January, the slashing of a French anti-terror patrol outside a Jewish community center in Nice in February, and the recent rise of anti-Semitism across Europe.Were the attack on the Jewish bookstore to have been executed as planned, it would have been horrific, to say the least. One can only wonder whether Western governments will be able to continue to gain a preemptive upper hand on the logjam of home-grown extremism, and that borne elsewhere.Previous: French Soldiers Attacked Outside Jewish Center\nRelated: Why Is the Islamist Death Cult So Appealing?