They are unlikely partners: the world's biggest democracy and its biggest communist state. Yet the alliance between India and the Soviet Union -- highlighted by the visit here of Prime Minister Rajiv Gandhi -- seems to have served the interests of both countries.
Mr. Gandhi obtained new agreements on scientific and technical cooperation until the year 2000, and Soviet credits for 1 billion rubles (about $1.5 billion) to finance Indian purchase of Soviet goods.
The agreements are typical of the relationship the two countries have forged over the last three decades. Under them, New Delhi receives Soviet arms and development assistance. Moscow has an important ally in the Indian subcontinent and the ``nonaligned'' movement. And two-way trade flourishes.
Gandhi describes the Soviet Union as ``a steady and trusted friend.'' Soviet leader Mikhail Gorbachev says the peoples of the two countries have a ``definite spiritual affinity.''
In some measure, the closeness of the two countries is a result of their estrangement from other Asian nations notably China and Pakistan.
Moscow uses its ties with India to counter Chinese influence in Asia. And India relies on the Soviets for weapons because the United States supplies India's chief rival, Pakistan.
In fact, Soviet stock with the Indians soared when Moscow backed India in its war with Pakistan in 1971.
The Soviets subsequently built upon that, expanding the relationship to include cooperation in a number of economic and scientific fields. Now, the relationship with India is based on much more than mutual antagonism toward third parties. It is perhaps one of Moscow's biggest foreign-policy successes.
Much of this was engineered by the late Indian leader, Indira Gandhi. The Soviets want to ensure that the relationship is not eroded by her son, Rajiv, who took over after her assassination last year.
And Rajiv Gandhi, who arrived here May 21, is at pains to reassure them. His trip, which ends May 26, was carefully timed to balance a planned visit to Washington next month and a meeting with President Reagan. By coming here first, he signaled that closer ties to Washington would come at Moscow's expense.
The significance of the gesture was not lost on the Kremlin, which responded in kind. It mounted the sort of red-carpet reception reserved for its closest friends.
Gandhi, like his mother before him, did not directly criticize the Soviet occupation of Afghanistan. He said Afghanistan did come up during his meeting with Gorbachev, and he conveyed his country's views. ``Our position,'' he said, ``is very clear. We are not for any country interfering in the affairs of another country.''
An account by the official Soviet news agency Tass said the Soviet Union expressed similar views about ``southwest Asian countries,'' although it did not mention Afghanistan by name.
But the Tass account hinted at possible disagreement over the Soviet-backed Vietnamese invasion of Kampuchea (Cambodia). Tass merely said that the two sides exchanged opinions on the matter, and concluded that the ``only sensible way to a settlement'' was through ``constructive dialogue.''
Similarly, Gandhi did not criticize a Soviet naval buildup in the Pacific. Gorbachev, in turn, supported a key Indian goal -- the ``demilitarization'' of the Indian Ocean. India still harbors memories of US naval vessels mounting a show of force in the ocean during the 1971 India-Pakistan war.
But Gandhi did not show much enthusiasm for a Soviet proposal for an Asian security conference, similar to the European security conference that resulted in the 1975 Helsinki Accords.
It is an idea the Soviets have been pushing, in one form or another, since Leonid Brezhnev met with Mrs. Gandhi in 1976. Then, as now, India endorses the idea of regional efforts to ensure peace but remains noncommittal about the Soviet proposal.
``Asian security is an old concept,'' Mr. Gandhi said. ``We are really for countries not intervening in areas outside their own.'' That attitude is, in part, an effort to avoid conflict with the Chinese, who are wary of Moscow's efforts to expand its influence in the region.