In October 1982, rebels fighting the Soviet-backed Marxist regime in Ethiopia asked the Central Intelligence Agency to support their uphill struggle. The answer was no.

That reply was most unexpected. Maj. Yosef Yazew, one of the dissident leaders, said in an interview that he had been encouraged by the U.S. Embassy in Khartoum, Sudan, to go to Washington to ask for the help in the first place.

But the CIA, he said, "told us the U.S. government has no policy and doesn't want to be involved in a program assisting military operations inside Ethiopia . . . . They just wanted information collection and propaganda activities."

Rhetorically, the Reagan administration's support for "freedom fighters" battling communist and communist-backed regimes around the world has been steadfast.

"Our party has been unstinting in its support of democratic development in the struggle against totalitarianism," Reagan said in a May 17 speech to the National Republican Heritage Groups Council. This period is "a critical turning point in the struggle between totalitarianism and freedom," he said.

But administration behavior toward anticommunist insurgencies has generally been a mishmash of ad hoc decisions, or nondecisions, as to who gets aid, with no apparent consistency or strategy. Of course, some aspects of the administration's covert assistance to various insurgencies probably aren't publicly known.

Of eight anticommunist insurgencies active in the Third World, the United States is providing military aid to two, in Nicaragua and Afghanistan. In Mozambique, the Reagan administration has decided to support the Marxist government, amazing Congress by proposing "nonlethal" military aid to help defeat a non-Marxist armed insurrection.

Other anticommunist resistance groups in Cambodia, Laos, Vietnam, Angola and Ethiopia get no overt military aid, although food aid is going, directly or indirectly, to those in Cambodia and Ethiopia.

Now, however, there is a drive within the administration and Congress to establish a policy and a strategy for helping armed anticommunist insurgencies, to show, as one top official put it, that "socialism is not irreversible" and "the Brezhnev doctrine is dead."

That doctrine, never labeled as such by Moscow, was named by U.S. officials for the late Soviet leader Leonid Brezhnev, who declared in 1968 after his troops invaded Czechoslovakia that the Soviet Union and other members of the "socialist commonwealth" could send "military aid to a fraternal country to thwart the threat to the socialist order."

Many in the West interpreted this as meaning that once a country joined that "socialist commonwealth," the Soviets would take any action, including military invasion, to keep it there.

Until now, the United States has followed a patchwork policy comprised of a contradictory combination of old Carter administration decisions (Afghanistan), congressional restraints (Angola) and independent bureaucratic initiative (Mozambique) or confusion (Ethiopia).

In Ethiopia, half a dozen Marxist and non-Marxist opposition groups have been fighting for 10 years either to topple the Marxist government or to set up independent mini-states. Despite innumerable opportunities to aid these rebels and revenge the loss to Moscow of an old U.S. ally in Africa, the Reagan administration is not known to have provided arms to any of the factions.

A 28-page memorandum submitted to the CIA by the Ethiopian Peoples' Democratic Alliance (EPDA) in October 1982 spelled out -- down to the cost of stationery -- a plan for training a first batch of 350 Ethiopian guerrilla leaders who would go into western Ethiopia to organize and spread the resistance under way there. The group requested $547,000 for the first six months.

When the CIA said no, the EPDA, a coalition of non-Marxist factions that split off from Marxist groups, shortly afterward ceased to function -- a victim of a harsh military repression, lack of outside support and internal squabbling.

But less than a year later, the U.S. government, alarmed by reports of pending widespread famine in northern Ethiopia, launched a secret cross-border feeding operation that bypassed non-Marxist factions and sent food to the victims through the civilian arms of two Marxist-oriented guerrilla groups.

At the same time, the United States sent more than 325,000 tons of food, worth $178 million, to the Marxist government in Addis Abbaba and U.S. private voluntary relief organizations working with it to stem the worsening famine.

These inconsistencies illustrate the swings of a policy caught between conservative hard-liners in the administration and Congress who are implacably hostile to the central government there, and pragmatists still hoping to win Ethiopia back from the Soviets with inducements.

In Mozambique, the same U.S. factions are clashing over administration proposals for $15 million in economic support and $3 million in military assistance to the Marxist regime for fiscal 1986.

Last year, conservatives in Congress killed the administration's $1 million military aid request for that southern African nation. This year, Sen. Jesse Helms (R-N.C.) has attached an amendment to the 1986 foreign aid bill that conditions military aid on free elections, an improved human-rights record and a cut in the estimated 1,500 to 2,000 Cuban and east-bloc military advisers to 55 -- the same conditions and same limit on U.S advisers attached by liberals to aid to El Salvador.

Since none of these demands are likely to be met, the amendment probably kills the military-aid request.

For years the administration has turned its back on the Mozambican anti-Marxist opposition movement, Renamo, and sought instead to woo the government under Samora Machel away from its Marxist domestic and pro-communist foreign policies.

The rationale has been first to promote detente between white-ruled South Africa and its black-ruled neighbors, and then to take advantage of Mozambique's show of interest in greater ties to the West in hopes of changing its Marxist orientation.

In Angola, the administration is barred by a 1975 law from giving assistance to Jonas Savimbi's anticommunist National Union for the Total Indpendence of Angola (UNITA). The administration has made no push to reverse this legislation.

During the 1975-76 civil war in Angola, the CIA channeled about $32 million to UNITA and another group, the National Front for the Liberation of Angola (FNLA) in a bid to prevent the Cuban-backed Marxists now in power from winning. The FNLA subsequently collapsed, but UNITA is stronger than ever.

Again, the administration's rhetorical backing for anticommunist insurgencies has been overshadowed by the dictates of its policy of detente in southern Africa. This seeks to gain the Angolan government's cooperation for a regional settlement that would send 25,000 Cuban troops home and gain independence for neighboring Namibia.

In Asia, Congress has taken the lead away from the administration in proposing overt humanitarian aid to rebels in Cambodia and Afghanistan. The Senate has approved $15 million for the Afghans, and the House Foreign Affairs Committee has voted $5 million for two noncommunist rebel groups in Cambodia.

Rep. Stephen J. Solarz (D-N.Y.), sponsor of the Cambodia-aid provision, argues that the United States must help build an effective noncommunist resistance movement as an alternative to the brutal Khmer Rouge, the main rebel force fighting the Vietnam-backed Communist regime in Cambodia.

Earlier, the United States was reported to have funneled some food aid to the Khmer Rouge through the Thai army as part of its overall humanitarian-assistance program to Cambodian refugees camped just inside Thailand. Congress cut off that aid in 1980.

Regarding Afghanistan, Congress is concerned that covert aid may not be reaching its intended recipients and is considering $15 million in overt nonlethal aid. Congress has appropriated $380 million to $400 million for covert aid through the CIA to the Afghan rebels since the Soviet invasion in 1979, according to the Federation for American Afghan Action, a support group.

At least another $250 million is expected this year, the federation says.

The Reagan administration took over and vastly expanded a Democratic policy of aiding the Afghan rebels. But limits apparently have been placed on the sophistication of arms that may be provided, with antiaircraft missiles capable of dealing with Soviet gunships and aircraft in short supply.

The State Department is against changing the U.S. military aid program to the Afghan rebels into an overt operation, a stand that Sen. Alfonse M. D'Amato (R-N.Y.) has attacked as "incredibly convoluted."

"The Soviets know what we're doing" covertly, and it's "ridiculous, absolutely ridiculous" to pretend they don't, D'Amato said at a May 8 hearing of the Senate Appropriations subcommittee on foreign operations.

D'Amato summed up the status of U.S. efforts to aid insurgent groups worldwide: "We have such a piecemeal theory. We hop from crisis to crisis . . . like little kids." D'Amato's frustration is widely shared on Capitol Hill and in many parts of the Reagan administration as well.