After he submerged fifty bullets in pig’s blood, the notoriously brutal general John J. Pershing executed forty-nine captured terrorists, sparing one so that he might run and tell other militants in the Philippines the sordid tale—or so the lore goes.

U.S. president Donald Trump recalled this fable—which he believes to be fact—in the wake of the Barcelona terror attack on Thursday, a story that numerous historians discredited each time Trump invoked this odd hero worship of Pershing in his presidential campaign.

At least fourteen people are dead and a hundred injured after a van weaved through throngs of people huddled along the bustling Ramblas, a famous tourist destination in Barcelona, Spain. “Study what General Pershing of the United States did to terrorists when caught. There was no more Radical Islamic Terror for 35 years!” Trump posted to Twitter, where he often remarks on current events and domestic and foreign policy.

Within hours of the attack, the terror network ISIS released a message on its Amaq news site claiming responsibility for the tragedy—without, however, providing any evidence of coordination with the perpetrators. Spanish law enforcement arrested two suspects in connection to the attack. Although the van driver, who jumped from the vehicle and escaped on foot, remains at large and the issue is mired in mystery, in the past, European leaders responding to similar vehicular attacks have been measured in their response.

The Spanish government should follow suit.

Since September 2001, when nineteen hijackers directed commercial airliners into the World Trade Center and the Pentagon, the United States has been at the forefront of an international fight against violent extremism. And while the war on terror has met controversy for its deadly tactics—which have cost the lives of innumerable civilians—and confronted battlefield losses in both Iraq and Afghanistan, American presidents have always shown a willingness to lead, to cooperate with allies, and to rhetorically unite and comfort an embattled international community.

Trump’s comments represent a gulf where such leadership once existed, and leave our communities vulnerable. Not necessarily to increased instances of terror—there’s no evidence that Trump’s statements inflame ISIS any further than that of any other U.S. president. But rather, this dangerous rhetoric risks the values of liberal democracies and, in effect, those democracies themselves.

Europe faces a severe terror threat, particularly because of well-established jihadist networks in France and Belgium. New America, which catalogues data on foreign fighters traveling to (and egressing from) Syria to join ISIS, has identified a network of twenty-one militants that supported the ten attackers who conducted the 2015 Paris attacks, which killed at least 130 people and wounded scores more.

What’s more, the continent’s proximity to the Middle East puts European nations at risk of attacks by militants returning from Syria. According to New America’s data, seven other returnees were arrested for plotting attacks prior to the Paris attacks.

But ISIS’s greatest strength is its cult of personality. The group’s ideology has inspired a number of attacks in Europe and the West more broadly, with ISIS-inspired attacks emerging as the deadliest threat to the United States. In June 2016, when Omar Mateen walked into a gay nightclub in Orlando, Florida, and gunned down forty-nine patrons, the deadliest terror attack in America since 9/11, he pledged allegiance to the Islamic State. ISIS bolstered this pledge by later claiming responsibility for the mass shooting.

However, though Mateen expressed sympathies with terrorist groups on his Facebook account, there is no evidence that he was affiliated with the group prior to his attack, nor that ISIS financed, directed, organized, or in any way coordinated Mateen’s mass murder. While the investigation of the Barcelona attack is still ongoing, it may prove to be another such instance of ISIS’s ideological tentacles reaching toward the West and radicalizing impressionable minds on the ground.

How the international community responds to this growing threat is incredibly important. European citizens, especially, are fatigued from these attacks and the subsequent admonitions by their leaders to stay strong in spite of the violence and national trauma.

After three successive attacks in Germany in July 2016, German interior minister Thomas de Maizière reminded the German populace to “stay levelheaded” and “keep calm.”

François Hollande, the French president at the time of the vehicular attack in Nice that slaughtered eighty-four, called for national unity in response to the tragedy and lamented the “desecration of democracy” that the attack represented.

In both of these countries, far-right political parties used these attacks to stoke anti-Muslim sentiment, threatening to swing their presidential elections in favor of radical populists akin to those in America and the United Kingdom. European and American citizens have mistakenly turned their ire against refugees fleeing the Syrian crisis for Europe. As a result, anti-Muslim violence is plaguing the United States and its allies.

Two vehicular attacks targeting Muslims occurred in the UK and Sweden within the same week in June. A Swedish citizen and alleged neo-Nazi drove his car into a demonstration of Iraqi refugees who were protesting the country’s new laws for asylum. And days later, Darren Osborne, a British citizen, mowed down a congregation of Muslims leaving a mosque in North London during Ramadan.

Meanwhile, a 2017 civil-rights investigation conducted by the Council on American-Islamic Relations (CAIR) found that between 2014 and 2016, hate crimes targeting Muslims increased by 584 percent in the United States.

Spain, for the most part, has avoided the terrorist violence that has befallen other areas of Europe. But with the Barcelona attack, it joins an unfortunate club. As a transit point for foreign fighters traveling to and from Syria, and with reports suggesting that ISIS is investing more resources in translating its propaganda into Spanish, Spain may see more attacks like this in the future. Thus, it is imperative that, in the face of terrorism, Spanish leaders avoid the saber-rattling of America’s president and strike the measured tone set by their European counterparts.

Because to do the opposite isn’t just futile in combatting terrorism. It threatens to sow dangerous divisions at home.

Alyssa Sims is a program associate with the International Security Program at New America. She researches and writes about the U.S. drone program and terrorism-related issues.

Image: A man holds a Spanish flag while authorities, politicians and citizens observe a minute of silence in Malaga, Spain. Reuters/Jon Nazca