President Trump with Egyptian leader Abdel Fatah al-Sissi at the White House on Tuesday. (Ron Sachs/Pool/EPA-EFE/Shutterstock)

EGYPTIAN PRESIDENT Abdel Fatah al-Sissi is orchestrating constitutional changes that will make him a de facto dictator for life, while permanently enshrining military control over Egypt’s political system. He continues to hold tens of thousands of political prisoners, including at least a dozen U.S. citizens. He has reportedly agreed to spend $2 billion to buy 20 advanced Russian fighter jets, though Egypt receives $1.3 billion in annual U.S. military aid, and a purchase from Russia could incur sanctions.

So how did President Trump assess Mr. Sissi when he arrived at the White House for a visit Tuesday? “I think he’s doing a great job,” said Mr. Trump. “I think we’ve never had a better relationship — Egypt and the United States — than we do right now.

The president’s judgment might be attributed in part to ignorance; he claimed he didn’t know about Mr. Sissi’s effort to extend his presidential mandate to 2034, when he would be 80. By now, too, it has become clear that Mr. Trump is easily impressed by strongmen, from Vladi­mir Putin to Kim Jong Un. But the endorsement of Mr. Sissi is also part of a calculated, if crude, strategy: to blindly back Sunni Arab autocrats as guarantors of “stability” and counters to the Islamic State and Iran.

As a number of senators tried to point out to Secretary of State Mike Pompeo at a Tuesday hearing and in a letter, there are big problems with that policy. First, it ignores the many ways Mr. Sissi is acting against important U.S. interests, including the unjust imprisonment of numerous Americans. Second, it is wrong about stability: Mr. Sissi’s repression and his misguided economic policies are setting up his country for future upheaval — much as did the previous regime of Hosni Mubarak.

Mr. Pompeo defended Mr. Sissi by saying he had taken on terrorist groups in the Sinai Peninsula and defended religious freedom. But as two experts on Egypt, Stephen McInerney and Amy Hawthorne, pointed out in a recent article, Mr. Sissi’s support for the country’s large Christian minority has been mostly rhetorical: Restrictions on Christian churchbuilding and employment remain in place. Michele Dunne of the Carnegie Endowment for International Peace explained in another op-ed that, while failing to end the jihadist threat, the Sissi regime has persecuted women’s rights advocates and other liberal activists and warped the economy with huge construction projects controlled by the military.

Then there is Mr. Sissi’s flirtation with Mr. Putin, which, as the bipartisan group of senators said in their letter, “risk making [Egypt] a Russian dependency once again.” U.S. military aid is mostly designated for weapons purchases, yet Mr. Sissi would buy Sukhoi SU-35 jets in defiance of congressional legislation mandating sanctions.

As in the case of Saudi Arabia, Mr. Trump’s unreasoning cultivation of this Arab dictator requires congressional correction. Senators should act on their concerns by conditioning military aid to Egypt on cancellation of Russian arms purchases, the release of imprisoned Americans and a general easing of repression. That Mr. Sissi is sensitive to U.S. opinion was evidenced by his presence at the White House on Tuesday. Because Mr. Trump will not use U.S. influence, Congress must do so.