How did the Soviet Union react to the news of Prime Minister Aldo Moro's kidnapping, and his subsequent execution at the hands of the Red Brigades?

Just a quick note on sources: Google's newspaper archive search is excellent for getting a sense of how events were reported and framed at the time. It's mostly smaller metro and regional newspapers, but for major events you'll often notice that they used material from one of the major news agencies (AP, Reuters, UPI, etc.) so don't be put off by the masthead. Also, if you have a New York Times subscription, Times Machine is an absolute godsend.

From a quick search of coverage of the Moro murder, Russian state media stayed pretty quiet about the kidnapping, except to angrily deny accusations that they were involved and to point the finger of blame elsewhere. This is from UPI's Rome correspondent, published in the Bangor Daily News (see what I mean?) a little more than a week after the kidnapping:

Meanwhile, in Moscow, the Soviet press Thursday indignantly denied "clearly provocative and hostile" rumours that Soviet agents were involved in the Moro kidnapping.

"It is nonsense — utter nonsense. But still it is stubbornly pushed into the bourgeois press," said the official Communist Party daily Pravda.

"The fate of Aldo Moro is a source of concern in the Soviet Union too. He is known in this country as an active supporter of friendly relations between the U.S.S.R. and Italy," Pravda said.

And this is from the New York Times on the day Moro's body was discovered:

The only word from Eastern Europe so far was a brief dispatch by Tass, the official Soviet press agency, reporting the death without comment. Previously the Soviet agency had suggested that the kidnapping was a plot by both left-wing and right-wing extremists to provoke chaos in Italy, and Italian press reports that the terrorists had been armed by Communist countries were indignantly denied.

Now, there are a few reasons why the Soviets might have been circumspect in talking about Moro's death — namely, that Soviet intelligence had ties to the Red Brigades, and were already concerned that those might become publicly known.

For a bit of context: relations between the Soviet Union and the Italian Communist Party (PCI) deteriorated significantly under PCI general secretary Enrico Berlinguer (in office 1972-84.) By the mid-1970s, Moscow had come to view Berlinguer as a revisionist and his conciliatory political strategy in Italy as heresy.

The Soviets continued to funnel millions of dollars to the PCI until the end of the 1970s, but by the time of the Moro kidnapping the relationship was tense at best — in part because of tacit and material Soviet support for the Red Brigades, themselves a radical breakaway faction from the PCI.

To my knowledge, there's no firm evidence of direct Soviet involvement in the Moro murder. But the Czechoslovakian secret service, StB, was a longstanding benefactor of the Red Brigades, which fits a well-established pattern in Soviet intelligence operations: the intelligence agencies of Warsaw Pact and other communist states were frequently used as proxies for the KGB — particularly in the handling of relationships with insurgent groups abroad.

Berlinguer and other reformers in the PCI were anxious that if the Soviets were thought to be involved in the Moro kidnapping, it could also prove seriously damaging to the PCI. You can see hints of that anxiety reflected in Berlinguer's very deliberate distancing of the PCI from the murder, in that New York Times coverage I linked earlier:

Mr Berlinguer, the Communist leader, today described Mr Moro in terms never before used by a Communist politician about a leader of the Christian Democratic Party.

"A great democratic leader has fallen, murdered by an organisation of criminal terrorists," he said. "The republic loses one of its major statesmen, one of the personalities who have had the greatest impact on the recent history of our country."