AS HE welcomed Egyptian strongman Abdel Fatah al-Sissi to the White House last week, President Trump proclaimed that Mr. Sissi has “done a fantastic job in a very difficult situation.” The Palm Sunday bombing of two Egyptian Christian churches, which killed at least 44 people, ought to give Mr. Trump cause to reconsider. The attacks reflected not only the inability of the Sissi regime to defeat Egypt’s Islamic State affiliate, but also its failure to protect a vulnerable minority that has been singled out by the terrorists.

Egyptian security services had no reason to be surprised by the church attacks. Egyptian militants who describe themselves as the “Sinai Province” of the Islamic State recently issued a video promising to escalate attacks on Christians; a series of killings in the northern Sinai city of Arish in February prompted hundreds of Copts to flee. Big attacks on Christian churches in the past have come during services, including one in December at the Coptic cathedral complex in Cairo that killed two dozen worshippers.

Yet on a holiday Sunday, the regime was unable to protect even the Alexandria cathedral where the Coptic patriarch, Pope Tawadros II, was leading a service. A suicide bomber blew himself up at the church’s gates as he was being checked at a security station. The patriarch was uninjured, but at least 17 people were killed.

Preventing terrorism is challenging for any nation. But Mr. Sissi’s response to the latest attacks is indicative of why he has failed so exceptionally to stem the violence. Mr. Sissi declared a national state of emergency — and then quickly employed it to shut down media coverage of the attacks. “It’s not acceptable to have the incident aired repeatedly on television,” he complained, as if that were the cause of the security services’ failure to prevent the assaults.

Since seizing power in a bloody coup against a democratically elected government in 2013, Mr. Sissi has established the most repressive regime in Egypt’s modern history. Human rights groups say up to 60,000 people have been jailed, including thousands of secular activists, journalists and human rights workers who have no connection to extremism. Thousands more have been killed or disappeared by security forces, especially in the Sinai Peninsula, where journalists and other independent observers are effectively banned.

The intense repression has driven recruits into the terrorists’ ranks, particularly in the Sinai’s Bedouin communities. Attacks have steadily increased, averaging 70 per month last year, according to the Project on Middle East Democracy. But Mr. Sissi does not learn: One respected researcher who produced a prescient report predicting that the regime’s tactics would only increase the terrorist threat, Ismail Alexandrani, was arrested in late 2015 on charges of “spreading false news.” He has been held without trial ever since.

Mr. Trump may imagine that Mr. Sissi is a tough autocrat in the mold of Augusto Pinochet, able to extinguish opposition with brute force. The church bombings offer another warning that such a judgment is wrong. The Egyptian ruler is steadily leading his country toward chaos thanks to his massive and misguided repression. Mr. Trump tweeted Sunday that he was confident Mr. Sissi “will handle [the] situation properly.” If so, he’s destined to be disappointed.