Secretary of State Haig's warning about Russian sponsorship of international terrorism echo similar statements from the courageous Russian dissident Andrei Sakharov. Last June, Sakharov -- a man with considerable access to Soviet secrets -- urged that the West not overlook the links between the KGB and international terrorist groups. Astonishingly, there seems to be considerable skepticism in some quarters about the degree of "proof" linking the Kremlin to terrorist organizations. It may be useful to take a quick look at some of the most readily available evidence.

In a published interview with one of us a year ago, Gen. Jan Sejna -- a former high-ranking Czechoslovakian military official who defected in 1968 -- said that starting in the mid-60s terrorist training camps were established in his country under control of the KGB and Russian military intelligence (the GRU). At these camps terrorists from all over the world received paramilitary training. Among those who "graduated" from the camp at Doupov (near Prague) were two of the founding fathers of the Italian Red Brigades, Feltrinelli and Franceschini. When Sejna was asked aobut the degree of Soviet control, he said: "The budget came from the Soviet Defense Committee decisions, and we had to account for the funds on the basis of the defense committee plan. Under no circumstances can this be considered an autonomous Czech program. It was a coordinated program."

In 1974 an automobile carrying two known KGB officials through the streets of Brussels had an "accident," and Belgian security found in the automobiles a collection of documents that demonstrated the existence of an "autonomous central" in Vienna. This "central" carried out liaison operations with terrorists groups in Belgium, England, Holland and Italy. These contracts and assistance to elements of the Japanese Red Army moving through Europe.

Once the documents were discovered, European intelligence agents placed the Soviet Embassy in Brussels under unusually close survelliance, and they learned that within hours of the Russians' discovery of the loss of the documents, the Vienna "central" was dismantled. It was quickly moved to Libya.

West German officials were able to demonstrate that the kidnappers of Peter Lorenz (a leading German political figure) had received aid from East German intelligence sources. In addition, the German interior minister publicly denounced Cuban collusion with the Baader-Meinhof gang.

The official representative of the PLO at the United Nations has publicly confirmed that Palestinian terrorists receive arms, money and training in the Soviet Union.

Basque terrorists captured last summer in Spain told Spanish security officials that they had been trained in South Yemen by Cuban instructors under East German control. A similar pattern emerges from the testimony of recent Libyan defectors in Western Europe, who have spoken of nearly 20 terrorists training camps in Libya under Cuban and East German direction. According to one of these defectors -- again in a published report -- between 10,000 and 20,000 terrorists a year graduate from the Libyan camps.

The list could be extended at great length, but the basic point is simple enough: there is a great abundance of evidence showing the active Soviet role in international terrorism -- or all self-proclaimed movements of "national liberation" -- are under Soviet control or exist because of Soviet initiatives. And it certainly does not mean that the United States should oppose all such movements. But it does show that a great deal of the blood being spilled by terrorists all over the world is the responsibility of the Russians and that -- as Italian President Pertini put it a few weeks ago -- the impetus behind much of the terrorism in countries like Turkey and Italy is from outside those countries, and served Russian interests.

One has to wonder at the reticence of some members of the intelligence community in the West. Why are they so unwilling to produce the evidence they possess? In the case of smaller European countries, the answer is most likely a simple one: they fear Soviet power, and have no confidence in our ability to protect them. But for a country like our own, there may be a different explanation: given the crisis of the American intelligence community, our allies may not be sharing all their information with us. We have been told as much by the chiefs of several West European intelligence services.

But still, the ability of the United States to obtain photographic evidence from all corners of the world would indicate that the American government must have pictures of the terrorist training camps in the Soviet Union and in countries like South Yemen and Libya. We can sympathize with the desire of American officials to keep such evidence classified. But we cannot understand their recent suggestion that no such evidence exists.