President Trump on Thursday revived a widely discredited story about U.S. Army Gen. John Pershing following the van attack in Barcelona, Spain.
Trump first condemned the attack and assured Spain the U.S. "will do whatever is necessary to help."
The United States condemns the terror attack in Barcelona, Spain, and will do whatever is necessary to help. Be tough & strong, we love you!— Donald J. Trump (@realDonaldTrump) August 17, 2017
Forty-five minutes later, he followed up with this:
Study what General Pershing of the United States did to terrorists when caught. There was no more Radical Islamic Terror for 35 years!— Donald J. Trump (@realDonaldTrump) August 17, 2017
Pershing, who headed up the American Expeditionary Force in Europe during World War I, served as governor of the Moro Province in the Philippines during the U.S. occupation in the early 1900s.
He supposedly put a stop to the Moro Rebellion -- a series Muslim attacks -- by shooting the rebels with bullets dipped in pigs' blood. Some Muslims consider pigs' blood to be unholy.
Trump referenced the story at a campaign rally in February 2016, Business Insider reported.
"He had his men load his rifles, and he lined up the 50 people, and they shot 49 of those people. And the 50th person, he said: You go back to your people, and you tell them what happened. And for 25 years, there wasn’t a problem," Trump said at the rally.
Fact checkers including Snopes and Politifact have called the Pershing story into question.
Snopes noted that "Pershing seemed keenly aware that the best approach was not to take any action that would encourage religious fanaticism." The website also labeled as "false" a related claim that Pershing "discouraged Muslim terrorists in the Philippines by killing them and burying their bodies along with those of pigs."
"There is no evidence that Pershing himself committed these acts, there is nothing said about the use of 50 bullets dipped in pig's blood, and most important, there is no evidence to support Trump's claim that this tactic was effective in stopping violence — or that it would provide a useful policy today," Politifact wrote.
Thursday's incident is being treated as a terror attack by Spanish authorities, but they have not blamed "Radical Islamic Terror."
The Associated Press contributed to this report.