The war in Gaza and the polarization it is causing internationally are creating a major risk of terrorist attacks in the European Union over the December holiday season, Ylva Johansson, the bloc’s commissioner for home affairs, said on Tuesday.
The warning was a reflection of how in Europe, which in recent years has been shaken by terrorist attacks, anger over Hamas’s Oct. 7 massacre in Israel and the Israeli military’s increasingly deadly retaliation in Gaza has created new risks.
Ms. Johansson did not mention specific threats, but noted a stabbing on Saturday in Paris, where a German tourist was killed by a man whom the French authorities said had psychiatric disorders and was upset over the deaths of Muslims, including in Gaza.
Ms. Johansson said that the European Union would make available an additional 30 million euros for protection from terror threats, including for places of worship.
A European Commission official who requested anonymity because he was not authorized to speak about the issue publicly said that the warning was prompted by the spread of terror-related material online, by recent attacks or attempted attacks in European countries and by the decisions by multiple E.U. countries to raise their terrorism alert levels. The official added that authorities are watching for both antisemitic and anti-Muslim violence because of the war.
In October, a 6-year-old Muslim boy was stabbed to death outside Chicago in an attack that authorities called a hate crime tied to the war in Gaza.
In a report published before the war in Gaza began in October, Europol, the European police office, said that terrorism continued to pose a serious threat in Europe and that member states viewed jihadist terrorism as the most prominent threat. White extremists have also perpetrated attacks in Europe in recent years.
Christmas holiday events where large groups gather have been targets, such as in Berlin in 2016, when 12 people were killed in a terrorist attack at a Christmas market.
Bibi van Ginkel, an expert at the International Center for Counter-Terrorism in the Netherlands, said that tensions were rising because of the war in Gaza, which she said could have a trigger effect on people who were already sympathetic to extremist ideology.
“All of the sudden because of the events,” she said, “they may feel that they themselves have a duty to act and have a right to act.”