Antisemitism has been on the rise in both the United States and Europe since the outbreak of the Israel-Hamas war in 2023. But with the start of the Iran war, the number of incidents has sharply increased, notably in Europe. But who is behind these attacks? And what does it mean for the future of Jewish life on the continent?
One group has claimed responsibility for orchestrating the Liège, Rotterdam, Amsterdam, London, Heemstede, and Antwerp incidents: Harakat Ashab al-Yamin al-Islamia (HAYI), which translates to the Islamic Movement of the Companions of the Righteous. Little is publicly known about the group, which has only emerged since the war in Iran began, and has been spreading propaganda videos on a Telegram account created just last week to promote its alleged attacks. Late on Monday, a person representing the group told CBS News: “We’ll keep threatening U.S. and Israeli interests worldwide until we’ve avenged every child in Gaza, Iran, Lebanon, and the resistance nations.”
There’s some indication that HAYI is just the Iranian regime masking itself in the digital world. One European security source told Agence France-Presse that because the group was unknown before the war’s start, “[I]t is indeed likely at this stage that it is a front group” for the Islamic Republic. The Wall Street Journal reported on Wednesday that other European security officials have noted that HAYI’s logo, which resembles those used by Iran and Hezbollah, appears to have been made with generative AI. HAYI has also claimed responsibility for attacks that never happened, such as an alleged strike on a residential building in Greece, which local authorities say did not take place, along with the averted attack in Heemstede.
Investigators haven’t found any links connecting the suspected perpetrators in these attacks to HAYI, but they are thoroughly exploring Iran connections. Following the Rotterdam synagogue attack, Dutch Justice Minister David van Weel told the country’s parliament that authorities are investigating Iranian involvement in the attack, and that it appeared that the four suspects had been recruited.
Marc Knobel, an associate researcher at the Jonathas Institute in Brussels and a historian who has written numerous reports and books on contemporary antisemitism, wrote in an email to TMD that the threat of HAYI shouldn’t be downplayed. “Whether it is a structured group, a front used to claim responsibility, or simply a label, the underlying logic is familiar: outsourcing violence, obscuring responsibility, and claiming attacks against Jewish or Western targets while making attribution more difficult.” Knobel said that the toll of antisemitic violence seen this month in Europe likely indicates that “the level of risk has increased” for European Jews.
He explained, “hostile actors—whether state or non‑state—can seek to instrumentalize this conflict by targeting what they perceive as ‘Jewish’ or ‘pro‑Israeli’ interests in Europe.” Jewish community sites, such as synagogues and schools, are easy targets for such violent actors because “they are easy to identify, cannot be relocated, and carry, in the eyes of terrorists, a strong symbolic charge.”
These violent attacks are also the most visible symptom of antisemitism’s wider resurgence in Europe. A European Commission report released in January—based on a November 2025 survey of citizens from all 27 EU nations—found that 55 percent of respondents said that antisemitism was a problem in their country, up from 50 percent in 2018. Another 47 percent said that antisemitism has grown worse in the last five years. Meanwhile, 62 percent of those surveyed said that hostility and threats directed at Jews in public were a problem in their country, while 61 percent reported problems with antisemitic graffiti, vandalism, and cyberhate.
Rabbi Andrew Baker—the director of International Jewish Affairs at the American Jewish Committee and the personal representative of the Organization for Security and Co-operation in Europe’s Chairperson-in-Office on Combating Antisemitism—told TMD that, as much as the violence is alarming, he was also concerned by the “ambient antisemitism” that many Jewish residents feel in European cities; “not necessarily threat of physical attack or abuse, but verbal harassment [and] discomfort.”
According to Israeli government data, immigration from Western countries rose 81 percent between 2023 and 2025, with French aliyah (Hebrew for immigration to Israel) alone jumping roughly 45 percent in 2025. On the eve of the Holocaust in 1939, 57 percent of the world’s Jews lived in Europe. Today, the figure is around 10 percent and dropping. According to the Pew Research Center’s 2025 global religion report, the continent’s Jewish population fell 8 percent between 2010 and 2020 alone.
Similarly, though the Iran conflict has increased the rate of antisemitic violence, there’s no indication that peace in the Middle East would end anti-Jewish violence in Europe. As Knobel noted, “Even if a ceasefire or an agreement were to be reached, the conflict will leave behind lasting traces: networks, propaganda, narratives of ‘revenge’ or ‘redress’ that can continue to inspire violent action.” He added, “the war in Iran acts as an accelerator or catalyst of an already existing threat; it does not create it ex nihilo, and its end will not automatically make the danger facing Jews in France disappear.”
Following the attacks, European nations have taken to increasing the security presence at Jewish sites and communities. On Monday, Belgium stationed 200 soldiers to stand watch outside the Israeli embassy in Brussels, a Jewish museum, and Jewish schools, which Belgian Defense Minister Theo Francken stressed is “not replacing anything—this is in addition to the police force.” The Netherlands has similarly strengthened security presence at Jewish sites, with Amsterdam-based Rabbi Menno ten Brink telling the New York Times last week, “We’re being protected at a very high level.” He added, “It’s unimaginable that it’s necessary.”
Baker acknowledged the reassurance such measures provide, but framed them as a floor, not a solution. “Having that in place certainly wins over whatever nervousness you have of living in a kind of semi-police-protected situation,” he said. “But people are thinking beyond this immediate security challenge. How do you change the overall environment? How can you use education to improve the situation, to fight antisemitism?”
Knobel outlined three areas where authorities can act beyond security theater. The first is preventive intelligence: cross-referencing tips with online propaganda material. The second is legal: deploying counterterrorism laws early, cutting off funding sources, and neutralizing terror cells before they act. The third is coordination between intelligence agencies and Jewish institutions, which he said “often detect the first signs of scouting or suspicious behavior around sites” before law enforcement does. As Baker put it: “Security is the immediate need, but it’s not the solution.”
