After months of uneasy relations, which included the cutoff of U.s. aid and the burning of the American Embassy in Islamabad, the United States once again is preparing to "tilt" toward Pakistan as part of its efforts to counter Soviet moves in the unstable Southwest Asia region.

Within the Carter administration, no one actually has used the word "tilt" -- a controversial term purportedly uttered by former secretary of state Henry A. Kissinger to describe U.S. policy during the 1971 war between India and Pakistan.

But that's the thrust of administration efforts to clear the way in Congress for renewed military and economic aid to President Mohammed Zia ul-Haq's government as part of the U.S. response to the Soviet invasion of Afghanistan.

On Thursday, State Department spokesman Hodding Carter, noting that "every situation creates its own changed conditions," insisted that the administration feels it always has had "a warm relationship" with Pakistan despite differences on "some specific issues."

He didn't elaborate. But, in the past year alone, these differences have included a cutoff of U.S. aid because of Pakistan's moves toward producing an atomic bomb, the Zia regime's execution of deposed prime minister Zulfiqar Ali Bhutto despite a personal plea by President Carter for clemency, the attack on the U.S. Embassy that caused the death of two Americans and a subsequent large-scale evacuation of U.S. dependents and nonessential diplomatic personnel.

Yet, although it outwardly looks like a drastic swing of the policy pendulum, the new U.S. drive for close ties with Pakistan actually is characteristic of the up-and-down relationship between the two countries ever since Pakistan, a Texas-sized country of 77 million, became independent in 1947.

In the ensuing years, Washington has sought repeatedly to stay on good terms with Pakistan because of U.S. desire to maintain a balance of power on the Indian subcontinent and the wider Southwest Asia area.

In general, U.S. ties with the military regimes that have controlled Pakistan during most of that time were close. But they frequently have been subjected to severe jolts caused by Pakistan's internal instability and the resulting erratic shifts in the country's foreign policy.

The trouble began in the early 1960s, when Pakistan, despite its membership in the U.S.-sponsored CENTO alliance, began developing close links with China, then regarded by Washington as a potentially dangerous enemy.

The policy contortions of that period caused the United States to cut off aid to Pakistan in 1966, and Washington, for different reasons, has been turning the spigot on and off fitfully ever since.

In 1971, when the secession of East Pakiston (now the independent state of Bangladesh) caused a war between India and Pakistan, the United States, although officially pledged to neutrality, took a number of measures -- the "tilt" described by Kissinger in secret documents -- aimed at bolstering Pakistan's position.

That was done because of the Nixon administraiton's feeling that India, which ultimately won the war, was too close to the Soviets and that an assertion of India's supremacy in the subcontinent would give Moscow too much influence in the region.

In the mid-1970s, U.S.-Pakistani relations began to nosedive again because of the antiwestern policies of Bhutto, who became prime minister in the aftermath of the war. When Bhutto was overthrown by the military and Zia became president in 1977, there were hopes that relations would improve once more.

But the strains persisted. The most overt reason was the clash between Pakistan's desire to match India in having its own atomic weapons capability and the Carter administration's drive against nuclear proliferation. Washington's inability to deter the Pakistanis led last April to the most recent clamp on U.S. aid.

Further problems were caused by Zia's desire to build support among the anti-western, fundamentalist Islamic forces gaining strength within his 96 percent Moslem country.

In late November, these forces burst into the open when Moslem mobs, already on edge because of the U.S. confrontation with neighboring Iran, and apparently believing the United States was behind an attack on a sacred mosque in Saudi Arabia, attached the embassy in Islamabad, setting it on fire and killing two of the American military personnel stationed there.

Although the Carter administration publicly absolved the Zia government of responsibility, Washington also decided that it would be prudent to lower the U.S. presence in Pakistan considerably, a move that now appears to be undergoing a sudden reversal in light of the more recent events in Afghanistan.