Christopher Steele, the former British spy whose claims about Donald Trump’s ties with Russia hold center stage in Washington right now, drives Republicans crazy.

They recommended the Department of Justice open a criminal investigation into his work. They released a formerly classified memo by Rep. Devin Nunes that vilifies him. And now they’re holding back a Democratic brief that tries to correct the record. Their Fox News minions have promised damning new revelations about Steele’s perfidiousness almost weekly.

What is it about Steele that possesses them so? Could it be that his findings from summer 2016 — when the world was still wondering why Donald Trump kept saying such nice things about Russia’s Vladimir Putin — proved so extraordinarily prescient?

Long before U.S. intelligence concluded Russians were trying to influence our presidential election, Steele had already sussed out the campaign’s basic ingredients. In June 2016 he already knew about ties between the Kremlin and Trump aides (specifically Carter Page and Paul Manafort). He knew Russian hackers had stolen documents from the Democratic National Committee to use against Hillary Clinton. Former CIA agent John Sipher noted that several of Steele’s early assertions “turned out to be stunningly accurate.”

Last Friday, Democratic Sen. Dianne Feinstein rebuked Republican colleagues for recommending the criminal probe of Steele. She accused them of trying to undermine the FBI and the investigation being conducted by Special Counsel Robert Mueller, and of attacking Steele as a way of “deflecting attention from collusion and obstruction of justice investigations.” Then she added: “Not a single revelation in the Steele dossier has been refuted.” Ouch!

Republicans keep trying to squeeze Steele into a role they think will neutralize him: Yet their version of reality is so at odds with everything we know about Steele’s life and career. We know he spent two decades as an officer in Britain’s Secret Intelligence Service , where he enjoyed the highest esteem from his bosses and his counterparts in the U.S. intelligence community. We know he spent long stints in Russia, where he built up his knowledge of the country and language and cultivated a wide-ranging network of contacts.

And we know one of his SIS jobs included working in Afghanistan with British and U.S. special forces hunting down terrorists. This is a man who put his life on the line for the sake of his country’s close alliance with the United States — a man who, in July and October 2016, correspondingly saw it as a matter of duty to approach old colleagues in the FBI when he realized he had stumbled onto a breathtaking threat to U.S. national security.

We also know Steele investigated the case of Alexander Litvinenko, the Russian defector who was assassinated — allegedly by the Kremlin — with a deadly radioactive poison in London in 2006. The risks are real. Some Moscow-watchers have followed the grim fates of a number of senior Russian officials likely involved in Operation Donald Trump. In early 2017, Oleg Erovinkin, an aide to Gazprom CEO Igor Sechin (arguably the second most powerful man in Russia), mysteriously died in the back of his car. After Steele took his reporting to the FBI, two key officials in the cyber department of the FSB (Russia’s security service, a successor of the KGB) and another cybersecurity expert were arrested and spirited away. They haven’t been heard from since.

This, too, suggests just how high the stakes are — so much higher than the world of Washington’s petty partisan crusades. This is the world of Kremlin intrigue, where mysterious deaths are a common tool of statecraft. This is the world that Christopher Steele had to plumb, at considerable personal risk to himself, to chart Trump’s illicit entanglements.

That the Republicans are so determined to destroy Steele’s reputation isn’t making life easier for him. Happily, he doesn’t have to do much to prevail against them. He merely has to endure. The truth will find a way. The members of Trump’s party who are smart enough to understand this must be terrified.

Christian Caryl is an editor with The Post’s Global Opinions section.