In “Communion,” Vance recalls a moment when he prepared to wage battle himself. In early 2020, as news emerged of a deadly virus spreading across China, “I drove to a sporting goods store and bought 1,000 rounds of ammunition,” Vance writes. “Then I went to Walmart and bought enormous bags of rice and flour, 20 pounds of ground beef, and excessive amounts of ketchup.” The cashier asked him if he owned a restaurant. “No. But the China virus is coming,” Vance replied.

In “Regime Change,” their new book about Trump’s second term, Maggie Haberman and Jonathan Swan of The New York Times write that Vance was something of a “doomer,” as Vance himself joked in private, that he was “always latching onto the most negative possibilities.” He worried, early and presciently, that divides over Israel and the Epstein files would threaten the MAGA coalition, and his fears lurched toward the conspiratorial. After the assassination last year of Charlie Kirk, the conservative activist and the vice president’s close friend, Vance’s “instincts told him that there was a larger plot behind the murder,” Haberman and Swann write. “He went down countless online rabbit holes, becoming so consumed by the videos and the theories that his wife, Usha, told him she was worried about him.”

Vance’s fears are not just for the MAGA base, or for the nation, or for the West; they are deeply personal, too. Throughout “Communion,” Vance confesses the “mortal sin of despair” and a constant “sense of fatalism” that the pain and struggles of his youth will be passed on to his own family. He worries that he will be a bad father or bad husband, that no one will take the trouble to visit his own gravesite in Kentucky. Vance’s religious conversion is partly an effort to assuage those fears.

“Therapy didn’t work for you,” his wife tells him. “But church does.”

When Samuel Huntington wrote of a clash of civilizations in the 1990s, he was depicting a cultural battle among the West, China, the Islamic world and other groups, divides that seemed to come alive with the Sept. 11 attacks. In contrast, Vance’s civilizational struggle, between Christianity and secularism, is found within the West.

“The threat that I worry the most about vis-à-vis Europe is not Russia, it’s not China, it’s not any other external actor,” Vance said last year at the annual Munich Security Conference. “And what I worry about is the threat from within, the retreat of Europe from some of its most fundamental values — values shared with the United States of America.”