Among other things, he was a KGB asset; By far the most important of the KGB's confidential contacts in South America ....
Which we know thanks to former KGB archivist Vasili Mitrokhin, who spent over a decade taking notes (and secretly taking them home with him) on what was in those archives. After the implosion of the Soviet Union, he was eventually able to leave Russia for the United Kingdom with those notes. Much of which information has been published in two books written by historian Christopher Andrew. One of which, The World Was Going Our Way (2005), contains quite a bit on Chile and Allende (from which the quote in the first sentence of this post is taken). More of what the KGB archives tell us about Allende is as follows;
He'd been well disposed to the Soviet Union since the early 1950s when, as leader of the Chilean Socialist Party, he formed an alliance with (the then illegal) Communist Party of Chile. Not that that was much help to his ambitions then, as in 1952 Allende only attracted 6% of his nation's vote. But, it was enough to get the notice of the KGB which had one of its agents (Svyatoslav Fyodorovich Kuznetsov--codename; LEONID), operating as a journalist, make contact with Allende.
A Soviet trade mission in 1961 made for yet more opportunitiy to cultivate Allende, whose electoral performance in the 1958 Presidential elections was much improved--3rd place. The KGB archives give Allende's friendship some credit for the breakthrough establishment of diplomatic relations between the Soviet Union and Chile in 1964. Now the Soviets have an embassy from which their KGB agents can operate. In the '64 election Allende garnered 39% of the vote. Ironically, more than he'd get in 1970 when, with a 3-way split of the vote, he was declared President by the Chilean legislature.
Also ironically, the Chilean Communist Party had their problems with him as an ally, as the KGB was told that he was 'a demagogue' and a' weak and inconsistent politician' who had Maoist sympathies--anathema to the Soviet dominated Chilean party. That his most conspicuous character traits were 'arrogance, vanity, desire for glorification and a longing to be in the spotlight at any price.' Which was prescient; those traits led to his eventually downfall by military coup.
Fidel Castro and his entourage also shared the Chilean Communists' disdain for Allende, noting his womanizing, tastes for fine wines, art, and well tailored clothing during Allende's trips to Cuba in the 1960s--when he would also become better known to Georgie Anne Geyer, with whom he would frequently swim at a Havana club.
But Allende's undeniable personal charm was an obvious political asset--even the U.S. Ambassador in Santiago found him appealing. So, when the 1970 election rolled around Moscow was ready to support his campaign, sending KGB personnel to Santiago to help him, and donating money to both his campaign and Allende personally. The archives show that probably over a half a million (1970s) dollars from the Soviet Union found its way to Allende. They even bribed a left-wing Chilean Senator not to run, and split the 'progressive' vote.
Which tactic may have been crucial, as Allende got only 36.3% of the vote. But it was more than either of his two opponents, Nationalist and Christian Democrat, got (35% and 27.8%). The Soviet Union's boy was then the first Marxist ever, anywhere, to 'win' a Presidential election. According to reports in the KGB archives, they wasted no time in controlling him; '...Allende was made to understand the necessity of reorganizing Chile's army and intelligence services, and of setting up a relationship between Chile's and the USSR's intelligence services. Allende reacted to this positively.'
The KGB didn't limit itself to Allende Señor either. It established separate lines of communication with Allende's wife and daughter Beatriz (who married a Cuban intelligence officer) too. Money from the Soviet Union continued to be funneled to Allende and his family. KGB head Yuri Andropov's reports to the Politburo left no doubt as to why; 'The KGB...is planning to use its capabilities to carry out a series of active measures in Latin American and other countries....'
In a later report spelling it out; '...establishing contact between Chile's and the USSR's armed forces, consulting on the use of Chilean atomic raw materials, organizing co-operation between the Chilean and Soviet security services, and other matters....' All under the noses of Richard Nixon and Henry Kissinger who were busily promoting detente with the Russians at this time.
It turned out to be money wasted, as Allende's grandstanding undermined his usefulness to Moscow, finally provoking the Chilean military to depose him. Which did leave the Soviets with another martyr for the cause, after Allende killed himself rather than take Augusto Pinochet's offer of safe conduct out of the country. True to form, the KGB exploited his death through gullible Western journalists like Anthony Lewis of the New York Times. That evil lives on to this day.