President Trump holds a chart highlighting arms sales to Saudi Arabia during a meeting with Saudi Crown Prince Mohammed bin Salman in the Oval Office of the White House March 20, 2018. (Evan Vucci/AP)

John Brennan served as director of the Central Intelligence Agency from March 2013 to January 2017.

It appears increasingly likely that Post columnist Jamal Khashoggi was detained and killed at Saudi Arabia’s consulate in Istanbul. There is still much that we don’t know, but if such an audacious act was carried out, it almost certainly would have required the approval of Crown Prince Mohammed bin Salman.

Since the passing of King Abdullah in 2015 and the ascension of Mohammed’s father, King Salman, to the throne, the crown prince has been on a relentless march to consolidate political power. He has used his royal standing as the king’s favored son to outmaneuver, sideline and effectively neuter both royal and nonroyal obstacles in his path. Taking advantage of his father’s diminished mental acuity, Mohammed gained the king’s acquiescence to push his uncle, Prince Muqrin bin Abdul Aziz, and his older and more senior cousin, Prince Mohammed bin Nayef, off the crown prince perch in short succession, grabbing for himself the role of day-to-day decision-maker in Riyadh.

His political consolidation campaign did not stop there. The well-publicized detention and shakedown of more than 100 princes, senior technocrats and businessmen at the Ritz-Carlton hotel in Riyadh that began in November 2017, under the guise of an anti-corruption crusade, was akin to a single pot calling dozens of kettles black. The move was intended to root out and intimidate potential opposition as well as to fill Mohammed’s royal purse with more than $100 billion in funds needed to pursue his domestic ambitions and regional adventures, including his disastrous military foray into Yemen.

To leaven some of his aggressive political moves and gain popular support, the crown prince also spearheaded some long-overdue social initiatives, such as allowing women to drive, curtailing the activities of the much-resented religious police and breaking down some mixed-gender prohibitions. But here, too, he brooked no criticism of the pace and scope of social change, ordering the arrest of activists, including outspoken Saudi women, who dared to challenge him.

Khashoggi was a particular irritant to the crown prince. Khashoggi was widely known and respected inside and outside the kingdom for his literary talent, political acumen and principled opposition to Mohammed’s increasing authoritarianism and arrogance.

Several decades ago, Saudi intelligence and security services had a well-deserved reputation for heinous extrajudicial acts against Saudis and non-Saudis alike. Much of that sordid history was left behind when Nayef, the former crown prince, served as deputy minister and minister of interior from 2004 to 2017. But Nayef lost his security portfolio, and his ability to continue the professionalization of Saudi security forces, when he was deposed by Mohammed. The security forces now answer to the intolerant and vindictive crown prince.

As history has shown, authoritarian leaders such as Mohammed become increasingly paranoid over time and use the instruments of national power to eliminate real and perceived sources of opposition. By leveraging his absolute control over subservient internal security services, the crown prince has methodically intimidated and neutralized political opponents.

The news reports and Turkish government accounts of Khashoggi’s disappearance from the Saudi Consulate, and the contemporaneous arrival of two planeloads of Saudis, have the hallmarks of a professional capture operation or, more ominously, an assassination. As someone who worked closely with the Saudis for many years, and who lived and worked as a U.S. official for five years in Saudi Arabia, I am certain that if such an operation occurred inside a Saudi diplomatic mission against a high-profile journalist working for a U.S. newspaper, it would have needed the direct authorization of Saudi Arabia’s top leadership — the crown prince.

Maybe Mohammed thought that his close ties to the Trump administration and the virtual absence of U.S. moral leadership on the global stage would help protect him from fallout. In particular, a visceral, shared animus for the Iranian regime probably gave him the impression that the U.S.-Saudi relationship is bulletproof.

I am confident that U.S. intelligence agencies have the capability to determine, with a high degree of certainty, what happened to Khashoggi. If he is found to be dead at the hands of the Saudi government, his demise cannot go unanswered — by the Trump administration, by Congress or by the world community. Ideally, King Salman would take immediate action against those responsible, but if he doesn’t have the will or the ability, the United States would have to act. That would include immediate sanctions on all Saudis involved; a freeze on U.S. military sales to Saudi Arabia; suspension of all routine intelligence cooperation with Saudi security services; and a U.S.-sponsored U.N. Security Council resolution condemning the murder. The message would be clear: The United States will never turn a blind eye to such inhuman behavior, even when carried out by friends, because this is a nation that remains faithful to its values.