The former C.I.A. operative Jack Devine watched Donald Trump’s performance standing next to Vladimir Putin in Helsinki on Monday, and his first thought was, “There is no way Trump is a Russian agent.” The proof, he told me, was right in front of us. If Trump were truly serving as a Russian intelligence asset, there would have been an obvious move for him to make during his joint press conference with Putin. He would have publicly lambasted the Russian leader, unleashing as theatrical a denunciation as possible. He would have told Putin that he may have been able to get away with a lot of nonsense under Barack Obama, but all that would end now: America has a strong President and there will be no more meddling. Instead, Trump gave up his single best chance to permanently put to rest any suspicion that he is working to promote Russian interests.

During a three-decade career in intelligence, Devine ran the C.I.A.’s effort to get the Soviet Union out of Afghanistan, and then served as the No. 2 (and, briefly, acting head) of its clandestine service. Along the way, he tangled with, and carefully studied, Russian intelligence officers. He was involved in two major hunts for American intelligence operatives who were secretly working for the K.G.B.: Devine was the supervisor of Aldrich Ames, the C.I.A. officer who pleaded guilty, in 1994, to spying for Moscow, and he oversaw the investigation of Robert Hanssen, the F.B.I. counterintelligence officer who confessed, in 2001, to being a double agent. Hanssen, for instance, was like Trump, narcissistic, with a broad set of grievances about the many ways that his special qualities were not being recognized. But, unlike Trump, he harbored those grievances quietly and found satisfaction in secretly upending the system in which he operated. Trump shows no signs that he can be gratified by secret triumphs. He seems to need everyone, everywhere, to see whatever it is that he thinks deserves praise. His need for public attention is a trait that would likely cause most spies to avoid working with Trump.

There is no need to assume that Trump was a formal agent of Russian intelligence to make sense of Trump’s solicitousness toward Putin. Keith Darden, an international-relations professor at American University, has studied the Russian use of kompromat—compromising material—and told me that he thinks it is likely that the President believes the Russians have something on him. “He’s never said a bad word about Putin,” Darden said. “He’s exercised a degree of self-control with respect to Russia that he doesn’t with anything else.” Darden said that this is evidence that Trump isn’t uniformly reckless in his words: “He is capable of being strategic. He knows there are limits, there are bounds on what he can say and do with respect to Russia.”

Because the word kompromat is new to most Americans, and has been introduced in the context of a President whose behavior confuses many of us, it is natural to assume that it must be a big, rare, scary thing, used in extraordinary circumstances to force compliance and achieve grand aims. But, Darden explained to me, kompromat is routinely used throughout the former Soviet Union to curry favor, improve negotiated outcomes, and sway opinion. Intelligence services, businesspeople, and political figures everywhere exploit gossip and damaging information. However, Darden argues, kompromat has a uniquely powerful role in the former Soviet Union, where the practice is so pervasive, he coined the term “blackmail state” to describe the way of governance.

Kompromat can be a single, glaring example of wrongdoing, recorded by someone close to the Kremlin and then used to control the bad actor. It can be proof of an embarrassing sex act. Darden believes it is unlikely that sexual kompromat would be effective on Trump. Allegations of sexual harassment, extramarital affairs, and the payment of hush money to hide indiscretions have failed to significantly diminish the enthusiasm of Trump’s core supporters. But another common form of kompromat—proof of financial crimes—could be more politically and personally damaging.

Trump has made a lot of money doing deals with businesspeople from the former Soviet Union, and at least some of these deals bear many of the warning signs of money laundering and other financial crimes. Deals in Toronto, Panama, New York, and Miami involved money from sources in the former Soviet Union who hid their identities through shell companies and exhibited other indications of money laundering. In the years before he became a political figure, Trump acted with impunity, conducting minimal corporate due diligence and working with people whom few other American businesspeople would consider fit partners. During that period, he may have felt protected by the fact that U.S. law-enforcement officials rarely investigate or prosecute Americans who engage in financial crimes overseas. Such cases are also maddeningly difficult to prove, and the F.B.I. has no subpoena power in other countries. If, however, someone had evidence that proved financial crimes and shared it with, say, the special counsel, Robert Mueller, other American law-enforcement officials, or the press, it could significantly damage Trump’s business, his family, and his Presidency.

Alena Ledeneva, a professor of politics at University College London and an expert on Russia’s political and business practices, describes kompromat as being more than a single powerful figure weaponizing damning evidence to blackmail a target. She explained that to make sense of kompromat it is essential to understand the weakness of formal legal institutions in Russia and other former Soviet states. Ledeneva argued that wealth and power are distributed through networks of political figures and businesspeople who follow unspoken rules, in an informal hierarchy that she calls sistema, or system. Sistema has a few clear rules—do not defy Putin being the most obvious one—and a toolkit for controlling potentially errant members. It is primarily a system of ambiguity. Each person in sistema wonders where he stands and monitors the relative positions of friends and rivals.

Gleb Pavlovsky, one of the leading political thinkers in Russia, is known to be an adviser to Putin and well connected to the power structure. In a 2016 article in Foreign Affairs, he endorsed Ledeneva’s sistema framework. Many observers imagine Putin to be some all-powerful genius, Pavlovsky wrote, but he “has never managed to build a bureaucratically successful authoritarian state. Instead, he has merely crafted his own version of sistema, a complex practice of decision-making and power management that has long defined Russian politics and society and that will outlast Putin himself. Putin has mastered sistema, but he has not replaced it with ‘Putinism’ or a ‘Putin system.’ Someday, Putin will go. But sistema will stay.”

Ledeneva said that the key to understanding Trump’s interaction with sistema is to look at the people with whom he did business. “Trump never dealt with anybody close to the Kremlin, close to Putin,” she said. “Or even many Russians.” Trump’s business deals, she told me, were with tertiary figures. Sistema is rooted in local, often familial, trust, so it is common to see networks rooted in ethnic or national identity. My own reporting has shown that Trump has worked with many ethnic Turks from Central Asia, such as the Mammadov family, in Azerbaijan; Tevfik Arif, in New York; and Aras and Emin Agalarov, in Moscow. Trump also worked with large numbers of émigrés from the former Soviet Union.