For two countries as closely aligned as India and the Soviet Union, the undercurrent of tension between them is amazing and quite palpable in New Delhi. Friction has developed especially over trade, but also encompasses the policies of the pro-Moscow Communist Party of India.
These developments do not change the basic thrust of Indian policies toward the Soviet Union, but they are a reminder that the relationship is mainly a marriage of convenience. Members of the Indian elite say, almost with resignation, that given United States policies in the South Asia region and the geopolitical realities, the country has no option but to maintain close links with Moscow.
The Soviet Union is now India's largest trading partner and is its biggest supplier of arms. There are, of course, any number of persons in the ruling establishment in New Delhi and outside it who are greatly devoted to the special relationship with Moscow. But what has been described as a ''tiredness'' in this relationship is throwing up longer shadows.
Indo-Soviet trade has prospered over the years on a barter arrangement for balanced trade on the basis of settling accounts in Indian rupees. But after the first phase of Indian industrialization, the magic of the rising trade graph is dissipating, with India accumulating mounting surpluses.
With economic liberalization policies initiated by Prime Minister Indira Gandhi in the last two years, Indian importers would rather go to the West or Japan for modern technology. Soviet exports to India have therefore been languishing, except for such staple and welcome items as crude oil and petroleum products.
To make the point, the Soviets stopped buying cashew nuts and reduced textile quotas, creating major problems for Indian producers. Nobody in New Delhi believed the Soviet argument that they had to substitute almonds for cashews because they needed to buy almonds from Afghanistan to support that country.
India's large arms purchases greatly offset its other trade purchases, but the Soviets have been insisting that New Delhi buy more in the field of heavy machinery. The Indian government is committed to exploring ways of increasing machinery purchases from the Soviet Union.