After ringing alarm bells for months on the dangers of the US rearming of Pakistan, Indian officials are reacting with conspicuous silence to Washington's offer last week of a five-year military and economic aid package to India's traditional antagonist.
Since the Reagan administration took office, Prime Minister Indira Gandhi and her aides have been outspoken on the dangers of a subcontinental arms race, the heightening of regional tensions, and the possibility of an attack on India by a freshly emboldened Pakistan.
But India has been unusually taciturn in the aftermath of the broad US-Pakistan agreement announced last week, provoking speculation that India is quietly planning to one-up the Pakistanis.
Punctuating New Delhi's official silence was an announcement, originating in Moscow, that the Soviet Union's armed forces chief of staff, Marshal Nikolai Ogarkov, will lead a high-level military delegation on an official visit to the Indian capital today.
The Indian press is also speculating that the new US-Pakistan relationship figures in the contents of a letter dispatched by Mrs. Gandhi to Soviet President Leonid Brezhnev April 23 via India's envoy to Moscow.
Together, the developments have sparked rumors of an impending major new Indian arms purchase from the Soviet Union, India's major foreign supplier of military goods.
Last year India and the Soviet Union signed a $1.63 billion arms credit agreement for new equipment for all three Indian armed services branches at concessional rates Pakistan would love the US to match: 17 years to repay, 2.5 percent annual interest, and repayment in local currency rather than scarce foreign exchange.
A Foreign Office spokesman, who said he had been told not to comment on the US-Pakistan agreement, said he had no information on any upcoming Indo-Soviet arms deals.
Speculation also turns on another possible Indian demonstration of muscle flexing: a repeat of its 1974 detonation of a nuclear device. According to American press reports, intelligence sources have sighted renewed activity at the Rajasthan desert site of India's first nuclear explosion.
Actual, potential, or just plain rumored increases in Pakistani military strength usually provoke highly emotional and complicated responses in India, which has fought three wars with its western neighbor since the two countries were partitioned from the old British colonial empire less than 34 years ago.
Reaction to American arms aid is particularly intensive because, India asserts, Pakistan turned American-supplied arms against India in the 1965 and 1971 wars. "We are not afraid of Pakistan or its acquiring arms, but past experience has shown whenever it was given arms they were used against India," Mrs. Gandhi warned earlier this month.
More gentle explanations for India's recent nonresponse have been suggested by diplomats here. Among them is India's awareness of the long road ahead before any US-Pakistan agreement comes to fruition. Neither the details nor the dollar amounts of the economic and military aid package have been firmed up, according to both Pakistani Foreign Minister Agha Shahi and US Secretary of State Alexander M. Haig Jr.
India knows there will be congressional opposition to President Reagan's request for a waiver of US legislation that bars aid to countries suspected of developing nuclear weapons. The United States cut off aid to Pakistan in April 1979 when Western intelligence reports disclosed a clandestine nuclear program.
A US-Pakistan agreement could yet flounder, too, over the contents of Pakistan's military shopping list. Pakistani officials have long made it clear, in Islamabad and in Washington, that they want access to highly advanced aircraft and weaponry. But the United States generally restricts its third-world sales to less sophisticated armaments and to defensive, rather than offensive, gear.
India and the United States also are tangling just now over terms for ending their 1963 agreement on American fuel supplies for India's Tarapur nuclear power plant. The agreement appears dead, despite denials of any firm decision from both sides, but a major unresolved issue is India's claim to the right to reprocess American-supplied spent fuel still stored at Tarapur. Some observers believe India may figure that one battle at a time is enough, and hold its fire for the US-Pakistan agreement later.