Should US be in the rebel business? US aid to pro-Western guerrillas in the 1980s may be a direct reponse to Soviet expansion in the 1960s and '70s. But some still insist the policy is wrong. Intervening in others' affairs is immoral, these critics say. Others object to helping insurgencies they say have no grass-roots support, like the Nicaraguan contras.

In the 1960s and 1970s, there were no significant Western-supported insurrections. But there were a number of leftist revolutions, supported in varying degrees by Moscow. Several of these emerged victorious - Vietnam, Cambodia, Ethiopia, Angola, South Yemen, Mozambique, Afghanistan, and, of course, Nicaragua. And although some were never given the elevated designation of ``socialist'' states, the Kremlin clearly considered all of them irreversible gains.

And ``irreversibility'' had teeth. Over time, a strategy designed to ensure that these gains endured was discernible: timely arrival of major arms deliveries; East German security and intelligence assistance; Cuban, Vietnamese, or Soviet troops when necessary; money; and diplomatic support.

In large part, the so-called Reagan doctrine of the 1980s - supporting armed insurgencies against Moscow-backed governments - was a direct response to Soviet expansion.

Arkadi Shevchenko, former Soviet undersecretary-general of the United Nations, puts it this way: ``There is no question that Brezhnev's foreign policy emphasized expansion in the third world. [Superpower] d'etente never affected Soviet relations with national liberation movements, and the Reagan doctrine was entirely justified.'' The US debate

But even those who viewed the Soviet expansion as provocative acknowledge that the US response poses a basic ethical question: Is lethal support to anticommunist resistance movements in the third world morally acceptable in American foreign policy?

There is no consensus on this point.

According to Congressman Jack Kemp (R), the Reagan Doctrine is a clear continuation of a long American tradition of supporting those fighting for freedom from tyrannical political forces. He cites President Truman's support for anticommunist forces in Greece after World War II as a precedent.

But, according to many liberal commentators, democracies have no business aggressively interfering in the affairs of other nations, no matter what their form of government. ``The reason for opposition to the Reagan Doctrine is simple: The use of force by democratic societies is not the way to do things,'' says one analyst.

In this viewpoint, the larger casualty toll which accompanies external assistance from either East or West carries strong negative moral implications.

Yet consensus among mainline American political parties may be closer than generally thought. According to Robert Hunter, a leading foreign-affairs authority within the Democratic party, ``It's not the theory or principle of intervention which distinguishes Democratic from Republican views on the Reagan Doctrine. It's the judgment and application that matters.''

Afghanistan and Nicaragua represent the two ends of the spectrum of US political consensus.

``There is no dispute about the authenticity of the insurgency in Afghanistan, while there is in Nicaragua,'' Mr. Hunter says. ``There is no question in Afghanistan that Soviet-United States relations are involved. This is not so clear in Nicaragua. There is no dispute about goals in Afghanistan. In Nicaragua, the goals are an undefined mixture of regional security concerns and support for an overthrow of the Sandinistas in the name of democracy. In Afghanistan the means were viewed by the American public as appropriate and moral - and there was no debate. In Nicaragua, our tactics got us into trouble politically and in the region generally.''

Covert vs. overt policies

``It took all of two months for portions of the Afghan support operation to appear in the press - and that was better than all the others,'' laments an ex-intelligence officer. He and others wonder whether the US is institutionally capable of keeping such activities secret at all.

Mr. Kemp and many conservatives say the practice of bestowing covert support without Congressional participation, while perhaps necessary in certain cases, is not practical when US steadfastness is required for longer periods.

Former intelligence officers point out the downside to open policies. To be overly explicit can force Moscow to respond in kind, even when it is inclined to do otherwise.

And third countries through which aid is being funneled - or which are themselves a secret source of support - often insist upon some secrecy. ``Covert assistance is necessary because of the problems open support would cause for other African countries willing to help us,'' says Tito Chingunji, secretary for foreign affairs for the National Union for the Total Independence of Angola (UNITA). ``It is also important that our enemies don't know exactly what and how much we are receiving.''

But the record is clear. The US has great difficulty in sustaining total secrecy about any large-scale support program. The intense emotion and debate around such activity encourages leaks - either by opponents, to sabotage a program, or by proponents to prove its value.

A former Reagan administration official in the national security field says that an imperfect response to this quandary has emerged: A new ``art form,'' nicknamed by insiders the ``overt-covert'' program, is now an accepted means of doing such business. Essentially, this means the US will publicly acknowledge existence of a support program, but not divulge details. So far, this formula has provided a tolerable framework only for those operations which enjoy a general consensus.

The targets

Clearly, not all Americans share the Reagan administration's definition of what states should be considered enemies. Some feel the Sandinistas are a socialist government forced by US support for the contras to arm heavily and depend on Soviet-Cuban links. Without external pressures, this school of thought holds, the Sandinistas would probably succumb to economic realities at a time when Soviet largess is drying up. Likewise, some see no strategic threat from the socialist Angolan regime.

But ex-KGB official Stanislav Levchenko sees dangers in this evolutionary view: ``Historically, in quasi-socialist states, hard-line communists do seize power and pursue their own policies. Nicaragua would without doubt have intensified interference and destabilization of its neighbors if left without opposition.''

Opposition to the Reagan administration's techniques in backing antileftist insurrections clearly exists. But the major stumbling block to consensus is a definition of what regimes should be tolerated, which ones weaned from the Soviet bloc by political and economic means, and which ones contested by force.

Many thinkers of a liberal bent would opt for an evolutionary solution in all cases covered by the Reagan doctrine except Afghanistan.

Soviet perspectives

US support for insurgencies in Afghanistan, Angola, and Cambodia has forced hard decisions on the Soviet leadership, and, says one conservative US official, brought about a ``more mature Soviet policy.''

But with the exception of Afghanistan, ex-KGB officer Levchenko does not believe Soviet leaders see the various insurgencies as Western successes.

UNITA's Chingunji agrees: ``The Soviets are not taking the Angolan situation as a defeat. But they are ensuring the Cubans stay at the bargaining table.''

And according to former senior Soviet official Shevchenko: ``For the Kremlin, Afghanistan is definitely a political-ideological defeat and a military defeat. I don't believe Moscow acknowledges defeat in Angola, nor can it claim success. It is, rather, taking a much more flexible approach. Nicaragua is probably viewed as a Soviet success, and Cambodia is primarily a pragmatic approach to remove an obstacle to better Chinese relations as well as reducing the cost of support to Hanoi.''

What has been achieved?

And finally, we come to the basic question. Is the West, and particularly the US, better off because of its involvement in these disputes?

In terms of the East-West competition, most Sovietologists venture a cautious ``yes.'' Moscow is acknowledging the reaching of a high-water mark of the previous decade's expansionist policies, and is contracting certain overseas commitments. Some Soviet-allied regimes will probably be dismantled or altered in coming years. And this phenomenon is of immense historical significance.

But the human toll, unpredictable orientation of successor regimes, and the cost of internal American political divisiveness undeniably create reservations about this positive strategic trend.

Second of three parts. Next: The lessons learned.