Ramin Yektaparast, the main suspect in organizing an attack on a Jewish cultural center in Essen

Security officials expressed confidence that the synagogue plot was carried out on the instructions of the Revolutionary Guard. One German security official, who, like others, spoke on the condition of anonymity to discuss the case, called it an act of “state terrorism.” Although Europe’s biker scene may seem an unlikely source of agents for Iranian activities, using criminal gangs to add plausible deniability is “a cornerstone of [Iran’s] operational playbook,” said Matthew Levitt, a former U.S. counterterrorism official who is now a fellow at the Washington Institute for Near East Policy.