Reagan administration officials, facing delicate renegotiations over the fate of U.S. military facilities in four NATO countries and the Philippines, are worried that deep cuts in foreign assistance and the rising hostility of the foreign governments pose serious threats to continued American access just when the need for the bases may be growing.

Earlier this month, Spain formally notified the United States of its intention to cancel its military agreement expiring next May and Greece opened negotiations on what it says may be an entirely new agreement on U.S. bases and facilities in that country.

Also earlier this month, Philippine Foreign Secretary Raul Manglapus announced in Manila that any new agreement for continued U.S. access to the two largest bases it maintains abroad will depend on Washington's acceptance of "new conditions" banning nuclear weapons from them.

"We're dealing with a shrinking universe in terms of U.S. access to the world," said one State Department official, noting the increasing number of challenges to American bases abroad, the freedom of U.S. navigation in foreign seas and the presence of U.S. nuclear weapons in foreign lands and waters.

Dozens of air bases, ports, communications facilities and storage depots used by U.S. forces throughout the postwar period are at issue. Some, such as those in Turkey, are considered crucial to the North Atlantic Treaty Organization's defense of its "soft" southern flank against the Soviet Union. The bases in the Philippines -- at Subic Bay and Clark Air Base -- are the main U.S. counterweights to the rapid buildup of major Soviet naval and air forces at former U.S. bases in Vietnam.

"The United States has got to spend more time on educating {our allies} on the need for a security alliance and the meaning of the Western alliance. They want to reap the benefits but they don't want to be tainted with bases or nuclear weapons, to pay the political costs," the State Department official said.

The official was reflecting on what he called the "astrological coincidence" of overlapping negotiations for U.S. basing rights in Spain, Portugal, Greece, Turkey and, shortly, the Philippines.

Nonetheless, most U.S. officials seem to agree with Robert W. Komer, former ambassador to Turkey and a longtime presidential adviser on NATO affairs, who remarked in a telephone interview that he does not think there is "a worldwide campaign against our bases and certainly not one orchestrated by {Soviet leader Mikhail} Gorbachev."

Still, the coincidence of five sets of ongoing or pending base renegotiations is forcing administration policymakers and other U.S. specialists to concentrate on the political problems in each case as well as broader issues at stake.

Negotiations that began in 1985 now seem certain to drag on until 1991, creating major uncertainties about the ability of the United States to project its sea and air power, or maintain security ties in their current form with key allies in the Mediterranean and the Pacific.

Already, the United States has ended its military cooperation with New Zealand within the ANZUS (Australia-New Zealand-United States) alliance because it objected to the U.S. policy of refusing to confirm or deny the presence of nuclear weapons aboard visiting U.S. warships and planes.

The bases talks are taking place against a backdrop of arms-control bargaining between Moscow and Washington on a treaty to scrap all Soviet and American medium- and shorter-range nuclear missiles based in Europe. The treaty is scheduled to be signed by President Reagan and Gorbachev at a summit here Dec. 8-10.

By eliminating one category of weapons, the pending intermediate-range nuclear forces (INF) treaty has created new anxiety in Congress and Western Europe about Warsaw Pact superiority over NATO countries in conventional forces. The perceived danger of an imbalance has increased the concern here over U.S. access to bases in Europe.

Asked about the importance of U.S. bases in Spain, Defense Secretary Frank C. Carlucci noted during his confirmation hearing Nov. 12 that "they are an important leg of our overall ability to defend the southern flank in a conventional way."

Carlucci termed the negotiations "extremely important" and said he would be "glad to engage personally" in them.

Administration officials seem particularly concerned about the negotiations with Spain because of the political and psychological impact a U.S. withdrawal from bases there could have on the other southern flank countries and on possible future NATO-Warsaw Pact negotiations on reductions in conventional forces.

"If a NATO nation is seen forcing out a very sizable American military presence, that has resonance here and in Europe," one U.S. official remarked. This is particularly true, he added, "if you accept the American argument that coupling {of U.S.-NATO defenses} is based on the American presence in Europe."

U.S. officials concede that the success of U.S.-Soviet arms talks and Gorbachev's campaign of glasnost, or openness, has relaxed tensions and lessened the sense of a military threat to Europe from the Soviet-led Warsaw Pact nations.

"We're in less of a bipolar world and more of a multipolar world where regional threats are perceived as more serious than the Soviet one," an official said.

This diminished concern over the Soviet threat is reflected in the deadlocked negotiations over U.S. access to the Spanish bases and facilities. U.S. diplomats are spending much of their time these days "briefing them {the Spanish} on what the threat is and how a security relationship works and where Spain fits in," as an administration official put it.

Spain is demanding a vastly reduced American military presence and the withdrawal of the 401st U.S. Tactical Fighter Wing, consisting of 79 F16 fighter jets, from its base at Torrejon outside Madrid. The 401st constitutes the largest U.S. air unit in the Mediterranean area and the main backup force for Italy, Turkey and Greece.

Similarly, Greece has said negotiations on continued U.S. access to four bases and 20 other facilities on its soil must start "from ground zero," and Portugal has let it be known that if U.S. aid continues to decline, Lisbon may reconsider continued U.S. access to Lajes air base in the Azores.

Access agreements with Spain and Greece expire next year and with Portugal in 1991. A new agreement with Turkey assuring U.S. access through 1990 was negotiated last year and signed in March. But the Turkish government, also miffed about falling U.S. aid levels, has refused to ratify the accord.

Far more serious is the looming debate in the Philippines -- where three current or former U.S. servicemen were recently assassinated and communist insurgents have threatened more attacks -- over the future of the U.S. presence at Clark Air Base and Subic Bay Naval Base. The base agreement comes up for review next year and could be ended by the Philippine government after 1991.

Any insistence by the Philippine government on banning nuclear weapons could pose a major problem because of the standing U.S. policy of refusing to say whether such weapons are aboard its ships and planes, according to U.S. officials.

John Steinbruner, director of foreign policy studies at the Brookings Institution, called for greater flexibility and sensitivity to local political problems in U.S. base negotiations. He warned against making bases "a litmus test of alliance commitment" to the point where the United States inflicts "internal political damage" on its allies by demanding too much. "We have a tendency to do that," he said.

Meanwhile, administration officials, faced with deep cuts in the foreign aid budget, tend to blame Congress for U.S. difficulties in the various negotiations.

"The biggest problem we have had is Congress," one official said. "If I were to point my finger at one single cause of our problems that {budget cuts} is the cause."

The officials said most of the base agreements were struck with host governments on the premise that the White House would make its "best efforts" to obtain military and economic aid levels it has not been able to deliver. In almost all cases the shortfall has involved hundreds of millions of dollars.

U.S. security and military assistance is, in the words of one U.S. official, "the quid pro quo they expect" in return for granting bases and facilities to the United States.