It says something about the ingrained rivalry between the various fiefdoms of Russian espionage that the founder of Soviet military intelligence, Leon Trotsky, had an ice-ax driven into his head in Mexico by an agent of Stalin’s foreign intelligence service.

Ever since, in the long dark history of Soviet and Russian spookery the military’s Main Intelligence Directorate, or GRU, has been overshadowed by a succession of more powerful, famous and infamous organizations known by a succession of acronyms, most famously as the KGB and, since the collapse of the Soviet Union, the FSB and SVR.

But on Thursday the GRU suddenly emerged from the shadows when the waning Obama administration imposed sanctions on the four top-ranking GRU officers for their roles hacking the private email correspondence of the Democratic National Committee and Hillary Clinton’s campaign chief John Podesta. The entire spy agency, along with the FSB, was also sanctioned institutionally.

The Glavnoye razvedyvatel’noye upravleniye, as it is formally known, was founded in 1920, assuming the mantle of its prior incarnation, the Registration Directorate for Coordination of Efforts of All Army Intelligence Agencies, after the Red Army's fiasco invasion of Poland that year. Its first director, Yan Berzin, was appointed by Felix Dzerzhinsky, the inaugural head of Lenin's Cheka. Yet somehow, unlike the KGB, the GRU managed to endure the rocky transition from communism to democracy to authoritarian kleptocracy with its acronym intact.

In Soviet times, as historian and journalist John Barron argued, the GRU was wholly subordinate to the KGB. As Barron noted in a revealing 1974 book, “The GRU may not employ anyone, either as an officer or agent, without prior clearance from the KGB. In addition, the KGB uses coercion and bribery to recruit informants among GRU officers, just as it does in every other element of Soviet society. Moreover, the KGB can veto any proposed assignments of GRU personnel abroad.”

But historically there were plenty of those assignments to be made. “Virtually all Soviet military attaches belong to the GRU,” Barron observed, “as do a large number of the Soviet citizens staffing Aeroflot offices abroad.”

When Donald Trump’s spokeswoman Kellyanne Conway tells CNN, as she did Thursday, that Obama’s sanctions on GRU officers are pointless because the GRU operatives don’t travel much to the United States or keep any assets here, she’s missing the point. The heads of the GRU are comfortably ensconced in Moscow, but their networks overseas are extensive, very likely including now as in Soviet times the military attachés serving in the Russian embassy in Washington, D.C., and the Russian Permanent Mission to the United Nations in New York.

Today it is believed that the GRU has an enormous network of agents abroad, built up over decades and rivaling that of the SVR, Russia’s contemporary foreign intelligence service.

“The GRU has been always seen as a more competent, adventurous and ruthless service in comparison with the KGB or SVR,” said Andrei Soldatov, a Russian journalist who has covered his country’s intelligence services extensively.

***

In the early 1960s, the GRU was very much on the mind of the Kennedy administration.

For starters, Oleg Penkovsky, a GRU colonel and a close friend of then-KGB chairman Ivan Serov, was a double agent being jointly run by Britain’s MI6 and the CIA.

He had passed critical intelligence to the West about Soviet military capabilities and Soviet Premier Nikita Khrushchev’s overseas plans, particularly the bold decision to station nuclear missile bases in Cuba, which Khrushchev hoped the U.S. wouldn’t notice until it was too late. Washington had uncovered the construction of the missile bases on its own, using U-2 spy planes, but Penkovsky provided the original plans and other corroborating material.

When Penkovsky’s betrayal was discovered it cost him his life, and cost Serov his job. In the aftermath the KGB chairman’s replacement, Lt. Gen. Petr Ivashutin, staffed the GRU with KGB men rather than military officers, making it even more of a suzerainty.

Yet the Main Intelligence Directorate had its marked successes, too. Beginning in May 1961, Col. Georgi Bolshakov, who posed as the head of the Washington bureau of the Soviet news agency TASS, was assigned to palaver on a biweekly basis with Robert Kennedy.

As we know from the Mitrokhin File, an enormous tranche of handwritten internal documents smuggled out of the Soviet Union by KGB archivist Vasili Mitrokhin, Bolshakov cultivated the U.S. attorney general, who happened to be the younger brother of the president.

As Mitrokhin and his co-author Christopher Andrew wrote in The Sword and the Shield, “Bolshakov succeeded in persuading Robert Kennedy that, between them, they could short-circuit the ponderous protocol of official diplomacy, ‘speak straightly and frankly without resorting to the politickers’ stock-in-trade propaganda stunts’ and set up a direct channel of communication between President Kennedy and First Secretary Khrushchev. Forgetting that he was dealing with an experienced intelligence professional who had been instructed to cultivate him, the president’s brother became convinced that ‘an authentic friendship grew’ between him and Bolshakov.”

Robert Kennedy himself attested to the closeness of the relationship and later confronted Bolshakov, who had insisted that Khrushchev had no such belligerent designs on America’s hemisphere, when the evidence produced from Penkovsky and the U-2s made those denials untenable. The GRU colonel had been running a careful game of deception directly with the two most powerful men in the United States.

Finally, it was Main Intelligence Directorate, not the KGB, that snagged the highest-ranking American ever recruited by the Soviet Union. An intelligence advisor to the U.S. Army Chief of Staff, Lt. Col. Willian Henry Whalen, was arrested by the FBI in 1962 after having provided his handlers with a gold mine of extremely sensitive information about U.S. military capabilities and the thinking of the Joint Chiefs of Staff, much of it having to do with the familiar subject of how the U.S. gathers intelligence electronically. For all the severity of this breach, Whalen served just six years in prison.

***

The GRU’s fortunes waned considerably after the Cold War and, as of only three years ago, it was considered inside Russia as a mostly spent force. It had been severely weakened after 2008, some say, because KGB veteran Vladimir Putin was fiercely critical of the GRU’s performance during the invasion of Georgia that same year. Others attribute the locust years to a package of “reforms” which reduced the GRU’s staff by 1,000 and cut the agency divisions from eight to five. That is in the wider context of the General Staff itself being more than halved in size. Still, as other spy services’ coffers grew, the GRU’s budget was conspicuously diminished.

All that changed very quickly, however.

“Now they’ve come back,” a former CIA operative stationed in Moscow told The Daily Beast. “They’ve come back because Putin, like Stalin, likes to have a variety of organs around him that compete with each other. And their roles often overlap with the roles of the Chekists from the FSB or SVR.”

From Putin’s point of view, the GRU had one unmitigated victory: the seizure and annexation of Crimea in 2014.

***

More than those other two services, the GRU has been responsible for running Russia’s dirty war in Ukraine, making it Putin’s suddenly preferred “secret weapon,” as Mark Galeotti, a specialist on the Russian security services, wrote in Foreign Policy in 2014.

The Crimea takeover, he noted, was “based on plans drawn up by the General Staff’s Main Operations Directorate that relied heavily on GRU intelligence. The GRU had comprehensively surveyed the region, was watching Ukrainian forces based there, and was listening to their communications.”

And of the so-called little green men who mounted that takeover and later turned up to try a repeat performance in Donetsk and Lugansk in eastern Ukraine, many were actually officers in GRU Spetsnaz with extensive battlefield experience in Afghanistan, Chechnya, and the Balkans. An early giveaway was the characteristic Vintorez rifle that only the GRU Spetsnaz troops are outfitted with. Then came sanctions.

Igor Strelkov, the former commander of the “Donetsk People’s Republic,” was blacklisted by the European Union as a GRU operative, even though he has elsewhere stated on social media and in public speeches that he is a former FSB officer.

Harder evidence of the GRU’s expansive involvement in the Ukraine theater came in May 2015 when Evgeniy Erofeev and Alexandr Alexandrov, two GRU commandos arrested by the Poroshenko government for their orchestration of units in Lugansk, were exchanged for Nadiya Savchenko, the Ukraine army aviation pilot whose capture on native Ukrainian soil and subsequent show trial in Russia—complete with her flipping off the judge and waging hunger strikes—made her both a cause célèbre and an elected parliamentarian back home. Swapping a prisoner of an undeclared war for two spies otherwise disavowed as agents of that war was a particularly fine touch, even for Vladimir Putin.

Also noteworthy is the fact that the only Russian intelligence head to be sanctioned by the U.S. Treasury Department for the invasion of Ukraine was Maj. Gen. Igor Sergun, another former embassy attaché, whose appointment three years earlier as the lowest-ranking head of the GRU struck many as curious. Sergun died last year, apparently of heart failure (although naturally there are rumors in both Ukraine and Russia that he was murdered for a less-than-ideal managing of the “separatists” in the Donbass), and his replacement Igor Valentinovich Korobov now finds himself on a similar sanctions list, along with his three top deputy chiefs, this time for interfering with an American presidential election.

***

As it happens, that interference and ongoing hostilities in Europe share a common participant.

Two weeks ago, the intelligence firm Crowdstrike, found that the GRU had honed its cyberwarfare capability on the Ukrainian battlefield by delivering malware to an Android app created by a Ukrainian officer, Yaroslav Sherstyuk, to aid howitzer crews in targeting. It was distributed on military forums from the summer of 2014 through 2016. The app contained a new Android variant of malware implant called X-Agent, associated by Crowdstrike with “Fancy Bear,” the very same GRU team the firm earlier identified as having hacked the DNC and John Podesta’s emails.

Thus, Russian military intelligence has been able to monitor not only the approximate GPS positions of Ukrainian soldiers, but also gather their SMS messages, call logs, contact lists, and internet data. The scale of the infection is unknown. The creator of the app claimed that it had around 9,000 users, all operating the D-30 howitzer (a mainstay of Ukrainian artillery). There is no data indicating how many of those installations were the compromised versions.

This revelation, if confirmed, makes one wonder if the speed with which East Aleppo was retaken two weeks ago by pro-Assad forces in Syria similarly owes to electronic sabotage. Even before Russia’s direct military intervention in Syria, in September 2015, there were reports of GRU officers embedded with the regime. In one underreported case, a “former” operative, now a judge, was shot in the face while “vacationing” in the war zone.

Since Putin’s second war got underway, the duties of the GRU have become if not quite transparent then less plausibly deniable. One of the dozen or so Russian military fatalities sustained in Syria was that of Captain Fyodor Zhuravlev, a GRU special forces operator who was killed in action in November 2015. We can’t know how many assets the agency has since sent to Syria, but a likely estimate would be in the hundreds.

Putin’s secret weapon is not such a secret anymore.