Secretary of Defense Pete Hegseth has a longstanding fascination with the Crusades. That’s right, the Crusades: the series of late 11th to 13th century medieval wars in which Europeans fought to control the Holy Land. He has tattoos that reference the Crusades, which actually came up during his confirmation hearing in 2025. And his 2020 book is titled American Crusade. The final chapter is titled “Make the Crusade Great Again.”

Hegseth paints the Crusades as a “defensive war” in which Christianity had to react or face being overrun by Islam. According to professor of medieval history Matthew Gabriele, this is an extreme oversimplification of the actual history. And viewing the past in this way could have possibly dangerous ramifications on the current war in Iran.

Pete Hegseth’s obsession with the Crusades may seem like a personality quirk, like your uncle who is obsessed with World War II submarines. But when that worldview influences how a defense secretary thinks about modern conflicts, it stops just being about the past — and it starts shaping the future.

Vox producer Nate Krieger took a closer look at this “Holy War” to investigate the actual history of the Crusades and to understand how Pete Hegseth’s interest in medieval history might actually affect US foreign policy and the future of the war in Iran.

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