Mr. President,I am one of those still living who has most extensively investigated the abduction and decapitation, in February 2002, of your fellow American, Wall Street Journal journalist Daniel Pearl.After the killing, I conducted research and interviews in Islamabad, Karachi, Lahore, and Peshawar, which led the 2003 publication of my book Who Killed Daniel Pearl?In it I gave the name of the man who held the knife, four years before his confession in a special court in Guantanamo: Khalid Sheikh Mohammed, who was al-Qaida’s No.3 man and the probable architect of the Sept. 11 attacks.But, above all, I retraced in detail the machinations that drew Pearl to the Akbar Hotel in Rawalpindi; that lured and deceived him through a series of emails promising him an interview with Mubarak Ali Gilani, leader of the Jamaat ul-Fuqra and one of the inspirations for the founding of al-Qaida; and that finally led him, deep into Karachi’s Gulzar-e-Hijri neighborhood, to an isolated house in which Fazal Karim, Naeem Bukhari, and others were waiting to murder him.I arrived, then, at the firm conclusion that the brain behind the operation, the man who conceived it with an almost diabolical zeal, the one who served as the link between the various jihadist factions that cooperated to pull it off, was Ahmed Omar Saeed Sheikh, a British Pakistani who was immediately arrested, convicted, and imprisoned.Moreover, I adduced proof that this man, Omar Sheikh, was no ordinary criminal but rather an influential member of a galaxy of terrorist organizations that gravitated around al-Qaida. Educated at the London School of Economics, he had been Osama bin Laden’s financial adviser and bin Laden referred to him as his “favorite son.”And, finally, I will say that, because history often mocks us even at its most horrifying point, Sheikh paid homage to my work in a terrible and paradoxical way in his 2005 interview from prison with Massoud Ansari of the Pakistani magazine Newsline: “You can find details on my background in Who Killed Daniel Pearl?,” he told Ansari.“The book retraces my entire existence. The references are mostly negative, but Lévy did a huge amount of research.” (Read a facsimile of the printed interview here.)All of this is to say, Mr. President, that the announcement by Pakistan’s Supreme Court, on Jan. 28, that “no offense” could be held against Omar Sheikh and that he and his accomplices should be “immediately released” is, of course, an insult to Pearl’s memory and spit in the face of his family—especially his son, Adam, who was born just a few months after his father’s death. It is clearly another threat leveled at the courageous journalists who work in the most inhospitable places on earth. But, above all, it is such a towering judicial absurdity, such a rank insult to the most well-established truths, and such a clear contradiction of the criminal’s own confessions and of common sense that it must also be viewed as a provocation addressed at your country and, coming as it does at the beginning of your term, at yourself.Granted, this is not the first time the Pakistani regime has acted in this way.Corrupted by intelligence services that are themselves infiltrated by terrorist groups, and constantly falling back on its position as a key “strategic ally,” the regime is a past master of a double game that always features some version of the following claim: “We have to throw a bone now and then to a citizenry whipped into a frenzy by the tenets of political Islam; help us keep them at bay lest they be moved to dangerous acts.”According to my sources, that is, more or less, the message the regime was sending as recently as last April, when, during your predecessor’s term, the high court of Sindh province commuted the sentences of Omar and his accomplices to seven years (covered by the 18 years of preventive detention already served), without the American secretary of state, the attorney general, or President Donald Trump himself summoning the resolve to express anything more than their “deep concern.”And I am familiar enough with the methods of this gangster state to know that, when it agrees to discuss, reconsider, and ultimately reverse a court sentence or hand over one or another al-Qaida or ISIS militant who had been spending quiet days in a residential neighborhood of Rawalpindi or in a village in the tribal areas bordering Afghanistan, the decision always comes as part of a negotiation that yields, as if by chance, a delivery of F-16s, a bilateral trade accord, or a loan.Now, the question, Mr. President, is whether you will be complicit with the latest installment of this blackmail or whether you will decide, as Secretary of State Antony Blinken has firmly announced, that the assassins should be brought to justice in Pearl’s own country, whatever the cost.The objection will be made, of course, that no formal extradition treaty exists between the United States and the Country of the Pure.And you will certainly be advised, as have all of your predecessors, that the United States greatly needs its “strategic ally” to facilitate the talks with the Taliban in Doha, to supply the last contingents of your special forces in Afghanistan, or to forestall the nightmare scenario of proliferation of the nuclear material that Pakistan possesses in such great quantity.The truth, Mr. President, is that Pakistan, a bankrupt country, needs its ally as much as its ally needs Pakistan.The democracies cannot eternally retreat for fear that their resistance might bring even worse consequences.And, above all, it is my conviction that what is at stake here is perhaps the most precious possession of the United States: its values and the respect those values inspire.A cynical administration—one lacking in scruples and principles, one that seemed to hold the nation’s values, and itself, in low esteem—spent the past four years creating the impression that it was possible to trample on the American creed and its bravest exponents.As all those concerned by Daniel Pearl’s memory, I hope and pray you will reverse this.I hope and pray you will demand that Omar Sheikh be handed over.This is the only way that America’s true allies, those who share the same love of liberty, will regain their faith in the country’s calling.