Last spring a group of American civilians and military men played a Caribbean war game at the Pentagon.
Of those would-be decisionmakers ensconced in soundproof rooms, the military men were the most cautious or, some would say, the most realistic.
It was the admirals and generals who opposed suggestions made by civilian foreign policy experts that the make-believe crisis they faced together be resolved by a direct attack on Cuba, or by the dispatch of US troops to Central America.
According to a participant, the military men argued that dramatic actions such as these would not have the support of the American people and would call for a substantial and dangerous reduction in American forces elsewhere in the world.
There have been times when the rhetoric of high-ranking Reagan administration officials suggested that the US was preparing the way for a dramatic escalation of its involvement in the current crisis in Central America. It appeared to some observers at one point, for example, that the administration was thinking of blockading Nicaragua, or that it might ''go to the source of the trouble'' with direct military pressure on Cuba.
But when one talks to some of the Defense Department experts who would have responsibility for carrying out such acts of war, caution prevails. And when one gets past the rhetoric, the options, as seen by this administration, turn out to be fairly limited. The administration finds itself in a middle position, in effect advocating more of the same - more military and economic aid to El Salvador, which is fighting a war against leftist guerrillas, and more training for Salvadoran troops.
This is a position that is unlikely to please either hawks or doves. But no administration is likely to be able to afford, at least in domestic political terms, to do what some doves advocate, which is to keep their hands completely off El Salvador. On the other hand, however, most administration officials also clearly oppose going to the other extreme and directly attacking Cuba or Nicaragua.
The conservative weekly Human Events advocates overthrowing the Sandinista regime in Nicaragua. But barring a major escalation on the part of Nicaragua, that idea does not appear to be viewed by the administration as a serious option.
To many liberals, the best option would be negotiations with the Salvadoran guerrillas. But officials say they are opposed to giving the guerrillas in talks what they could not earn at the ballot box or on the battlefield. While publicly seeming to welcome Mexico's recent efforts to achieve a negotiated settlement, US officials say privately that they doubt the Mexican initiative will go very far.
Many observers outside the administration seem to think that the March 28 election for a constituent assembly in El Salvador will weaken the position of President Jose Napoleon Duarte, who is a moderate in the US view, either forcing him out of office or into a coalition with right-wing politicians. This would limit the administration's options even further, they say, making negotiations with the guerrillas even less likely. Others argue that Mr. Duarte may gain more legitimacy from the election, thus strengthening his hand.
In a recent interview with the Washington Post, however, President Duarte dismissed any suggestion that he would ever negotiate with the guerrillas.
Administration officials do not like to talk publicly about limits on their options, particularly when it comes to the possibility of dealing forcefully, and directly, with Cuba and Nicaragua. They would like to use their rhetoric to keep the Cubans and Nicaraguans guessing. Gen. Vernon Walters, a former Central Intelligence Agency official who is currently an adviser to Secretary of State Alexander M. Haig Jr., is credited with advocating ''calculated ambiguity'' on the part of the administration when it comes to Cuba and Nicaragua.
But by engaging in threatening rhetoric and failing, publicly at least, to rule out any options, the administration has shaken some members of Congress. It has thus possibly further limited its options.
As administration officials see it, they face what Nestor D. Sanchez, a deputy assistant secretary of defense, has called ''a choice among imperfect alternatives.'' Seen from Washington, neither a quick military solution nor a quick negotiated solution seems likely in El Salvador. Officials deny that they aim for a military victory. Instead, they say that they hope eventually to arrive at some kind of negotiations following the steady, long-term provision of more military and economic aid to the government of El Salvador, and more training for its troops.
Although it does not publicly acknowledge that it is the case, the administration also appears to be giving secret support to opponents of the Sandinista government in Nicaragua and to those who might be able to help disrupt the arms flow from Nicaragua into El Salvador. Officials do not indicateD however, that they consider such ''covert action'' a solution in itself but only that they see it as supplementing the military and economic aid programs in El Salvador. A look at the options helps to show why, despite the rhetoric, the administration finds itself somewhere between extremes: Direct military action
A military operation against Fidel Castro's Cuba or against Nicaragua does not seem to be in the cards at the moment, even if Nicaragua gets Soviet-built MIG fighter planes as the US expects it will. In the view of the US Defense Department, the American public would not support such an operation. Even if it did materialize, it would entail riscs for America's global military posture because US forces would have to be withdrawn from other vital regions to carry out the operation. According to one defense expert, Cuba is a ''much more difficult target'' than it was during the Cuban missile crisis 20 years ago.
Latin American nations and other countries friendly with the United States would probably condemn such a military operation, and it would make cooperation with the US more difficult. With support for the Cuban and Nicaraguan regimes faltering, such action might be just what those regimes needed to unite people behind them. It would also divert attention from Soviet actions against Afghanistan, Poland, and other nations.
''Everytime we flex our military muscles, Castro screams wolf and rallies people around him,'' says a Defense Department official. ''The Soviets would like nothing better than for us to attack Cuba. How could we be righteous about Poland and Afghanistan after that?'' Naval blockade
A naval blockade to shut off the flow of arms from Cuba and Nicaragua might look at first like an attractive option. But a blockade suffers from some of the same disadvantages that would be involved in a direct attack. It would be likely to require support from the American people for a period of many months, support that the Defense Department does not think would be forthcoming. Cuba and Nicaragua are believed to be capable of riding out a blockade, although, depending on how extensive it was, it might cause them hardship.
Navy Secretary John F. Lehman Jr. told reporters recently that a naval blockade aimed at cutting off arms shipments to El Salvador was technically feasible, but it would strain the US fleet. He also said that before engaging in such an act of war, the administration would have to make certain that the US Congress and the American people fully supported such an action. Defense experts think that the memory of Vietnam is still too fresh for many Americans to go that far.
In fact, a majority of Americans want the US to keep out of El Salvador, according to a New York Times-CBS poll releaped March 21. When asked what Washington should do in El Salvador, 63 percent said ''stay out.'' Sixty percent said they feared the US would ''get involved in El Salvador the way it did in Vietnam.''
What the US has done is to greatly increase its air and naval activities in the Caribbean. It has resumed aerial surveillance of Cuba and started reconnaissance flights over Nicaragua as well. It is seeking broader access to air fields and ports in the region and is widening its contacts with military men in regimes friendly to the US. All this activity could become one of the bargaining chips in any eventual negotiations with Nicaragua and Cuba over the reduction of military forces in the region. Aid and training
If American officials are to be believed, the chief thrust of their Central American policy remains one of aiding friendly regimes in the region, with the main emphasis on bolstering El Salvador.
Officials say that they do not expect these programs to lead to a military victory in El Salvador but that they do think the Salvadoran Army is doing better in its battle against the leftist-led guerrillas than many press reports would indicate it is. They expect further improvement in the Army's performance when a new Salvadoran battalion of nearly 1,000 men completes its training at Fort Bragg, N.C., and nearly 500 cadets return from training at Fort Benning, Ga. The Salvadoran armed forces are being expanded from a totalstrength of 25, 000 men to about 30,000.
Some US officials seem to be more concerned, meanwhile, about the deteriorating economic situation in El Salvador than they are about the military situation. As they see it, a continuing decline in the economy could undermine whatever military gains are made by the Army. On March 17 the Reagan administration sent a request to Congress for $128 million in emergency economic assistance to be added to $104.5 million already appropriated for the fiscal year ending Sept. 30. Military aid for fiscal year 1982 comes to $81 million.
President Reagan's recently announced Caribbean Basin initiative is aimed in part at drawing more American investment into the region. Not surprisingly, private investment in El Salvador has largely stopped. The flight of capital from the country over the past several years may come to more than a billion dollars.
In the face of cuts in domestic programs, Congress has been reluctant to appropriate more money for El Salvador. Much may depend on the performance of the Salvadoran Army and security forces in the coming months and on whether they reduce abuses of the civilian population.
Critics say that the US could do more to get El Salvador's government leaders to implement reforms and to discipline the Army and security forces. One of those critics, Robert Pastor, a member of the National Security Council staff under the Carter administration and now with the Brookings Institution, says the Reagan administration should threaten to reduce aid if concerns about human rights abuses and other matters are not met. Mr. Pastor says that a Carter administration threat to suspend aid in 1980, combined with a promise to increase it if economic reforms were promulgated, caused the civilian-military leadership in El Salvador to go ahead with the reforms. Secret action
Given its rejection of direct military action, it is not surprising that the administration has apparently decided to ''go to the source'' with covert, or secret, action to try to disrupt Cuban and Nicaraguan arms supply lines.
Without fully confirming that this is the case, a State Department official went fairly far. He said that since the supply of arms by Cuba and Nicaragua is covert, logic would lead one to conclude that the counteraction would be covert.
The official denied, however, that the US was giving financial support to the former national guardsmen from Nicaragua who are now stationed across the border from Nicaragua in Honduras and who have been launching raids into Nicaragua. The guardsmen are hated by many Nicaraguans. To be allied with them might prove to be more of a liability than an asset.
Administration officials have also denied that the US has any intention of trying to overthrow the Sandinista government in Nicaragua. Given the fact that the Sandinistas came to power on a wave of popular support, such an attempt might backfire. It might merely end up consolidating support for the regime at a time when that support is waning.
What President Reagan is reported to have approved is American assistance in the creation of a paramilitary force designed to disrupt arms supply lines from Nicaragua to El Salvador. Such a force would involve Latin American nations friendly to the United States, including Argentina. According to a report published in the New York Times on March 13, Americans would not be directly involved in the operations of such a force. What they would do is share intelligence with the force and point out targets.
The Times reported earlier that Reagan had also approved a plan to provide millions of dollars in covert funds to moderate political and economic forces in Nicaragua. The State Department subsequently said that the US was providing millions in aid to private noncommunist groups in Nicaragua, but that it was doing this openly. The department said that this aid to cooperatives, labor unions, business associations, voluntary organizations, and community self-help projects was given with the knowledge of the Nicaraguan government and will come to about $7.4 million in 1982. Economic squeeze
Even as it increases aid to El Salvador, the US is tightening its economic squeeze on Fidel Castro's Cuba. In addition to launching plans for an anti-Castro radio station, the Reagan administration has clamped new restrictions on trade with Cuba.
Some conservatives think that the administration ought to begin restricting trade with Nicaragua, although that could have the result of driving the Sandinistas even more closely into the arms of the Cubans. The United States is still Nicaragua's biggest foreign-trade market. State Department officials say that the Nicaraguans would like to see a resumption of suspended American economic aid.
Richard Araujo, an analyst for the conservative Heritage Foundation, has recommended, among other things, that the US withhold American support within multilateral lending institutions for all loans to Nicaragua. Liberals think this sort of action would merely further reduce whatever remaining leverage the US has with Nicaragua.
In the view of a number of observers, whatever the US does in the way of action against Nicaragua or Cuba should ideally be done in coordination with Latin American nations friendly to the US. But that is easier said than done.
Araujo has suggested that any naval blockade designed to stem the flow of arms to El Salvador by sea be carried out in cooperation with naval forces from Honduras, Panama, Venezuela, and Mexico together with other Latin American navies willing to participate. Colombian President Julio Cesar Turbay has called for an inter-American naval force to block arms supplies. But putting such a force together from among such a diverse group of nations might prove to be exceedingly difficult. To start with, the Mexicans do not share the degree of alarm that has been exhibited by the United States over the intentions of Cuba and Nicaragua.
And Abraham F. Lowenthal, secretary of the Latin American program at the Wilson Center in Washington, D.C., also points out the preoccupation of US policymakers with Fidel Castro's Cuba is not always shared by noncommunist leaders in the Caribbean.
In a recent paper on the Caribbean, Mr. Lowenthal said that these leaders ''typically perceive Castro as a primarily Caribbean actor, not mainly as a cold war instrument. At times they even find it useful to 'play the Cuban card' to derive increased legitimacy with domestic constituents or to strengthen third-world ties. The persistent failure by US government officials to be sensitive to Caribbean perceptions of Castro, and the US readiness to give the Cuban issue priority over the needs of the area, leads to recurrent tensions. Intensifying cold war measures in the Caribbean will, in all probability, damage US-Caribbean relations directly and may also reduce the chances of cooperating with other external powers - Canada, Mexico, Venezuela, and Organization for Economic Cooperation and Development donor countries - to promote Caribbean development.''
Mr. Lowenthal recommends that in its Caribbean aid programs the US work mostly through multilateral rather than bilateral channels and formulate a long-range approach that would focus primarily on the region's underlying social and economic dilemmas.
Some experts, such as Robert S. Leiken of the Center for Strategic and International Studies (CSIS) at Georgetown University, have suggested that military activity against Cuba and the Soviet Union consist of support for national resistance movements in places such as Afghanistan, Angola, Ethiopia, and Kampuchea (Cambodia). But with the exception of some limited, secret support for the Afghan insurgents, the administration has apparently not gone far in this direction.
Secretary of State Haig has hinted, however, that the Soviets cannot expect to remain invulnerable to counterpressure in areas close to their borders while supporting insurgencies close to the borders of the United States.
In a recent publication the liberal Center for National Security Studies, which is sponsored by the American Civil Liberties Union Foundation and the Fund for Peace, asserts there is evidence that the United States is now secretly providing financial and intelligence support to Chinese efforts to arm and train anti-Vietnamese guerrillas. Negotiations
Sentiment in the US in favor of a negotiated settlement of the war in El Salvador has been growing.
Earlier this month, the House of Representatives voted 396 to 3 in favor of ''unconditional discussions'' between the Salvadoran government and its guerrilla opponents.
Proponents of negotiation tend to believe that the US has got itself into a ''no-win'' situation in El Salvador. As a group of more than 600 students and faculty members at 10 leading American graduate schools of public and international affairs said in a recent statement, they fear that the Salvadoran government will require ''ever increasing quantities of military assistance and perhaps American combat troox4 mOder to survive.''
The US Catholic Conference (USCC), the policy agency of the Roman Catholic bishops in the United States, favors a ''political solution'' to the war. The bishops base their analysis on a conviction that the roots of the war can be found in conditions inside El Salvador itself. They do not believe, as the Reagan administration apparently does, that the driving force of the war can be found in Moscow, Havana, or Managua.
According to the USCC's Rev. J. Bryan Hehir, ''The continuing administration emphasis on the geopolitical aspects of the Salvador case keeps raising the stakes of the US commitment in El Salvador. This escalation of interest in turn narrows the range of political options which we could accept.''
Robert Pastor of the Brookings Institution favors negotiations in part because, in his view, negotiations may divide the Salvadoran left between those civilian politicians who believe in democracy and those guerrilla leaders who don't. He thinks the administration should embrace the peace proposal put forth in Managua Feb. 21 by Mexico's President Jose Lopez Portillo.
Lopez Portillo made three points:
1. The US should not threaten Nicaragua with the use of force.
2. Military forces in the region should be reduced in a balanced way. Former Nicaraguan national guardsmen training in the US or operating between Honduras and Nicaragua would be disarmed. Nicaragua would renounce the acquisition of new arms.
3. Non-aggression pacts would be signed between the US and Nicaragua and between Nicaragua and its neighbors.
Negotiations between the US and Nicaragua and possibly between the US and Cuba would follow.
Secretary of State Alexander M. Haig Jr. has told the Mexicans to try out these ideas on the Cubans and Nicaraguans and to convey to them additional US ideas on the subject. Mexican Foreign Minister Jorge Castaneda de la Rosa arrived in Havana this weekend to brief Cuban leaders on his recent discussions with Haig.
In the American view, the main flaw in the Lopez Portillo plan, at least as it was first introduced, was that it did not guarantee a halt to the flow of arms from Nicaragua to El Salvador.
The Mexicans have since agreed that this flow must stop. This has not, however, completely satisfied Washington's concerns, and it is clear that administration officials think it unlikely that the Mexican plan will succeed. The administration is skeptical, partly because it does not fully trust the Mexicans' view of the situation and partly because it does not in any way trust the Cubans, the Nicaraguans, and the Salvadoran guerrillas. In the administration's view, the guerrilla leaders, while representing a variety of backgrounds, are essentially ''radical, anti-US Marxists.''
In 1980, the guerrillas rejected a call for negotiations with the Duarte government and instead proposed talks only with the United States (''talks with the circus master and not with the circus clown,'' was the way they put it) - and only if the Salvadoran armed forces were ''restructured'' and top officers dismissed.
That was clearly unacceptable to the Reagan administration and to the Duarte government. But the left subsequently dropped its two preconditions and proposed unconditional negotiations.
Some liberal scholars, such as William M. LeoGrande, director of political science at American University's School of Government and Public Administration, say the administration ought to take up this offer and that in addition it should move toward a normalization of relations with Cuba.
The administration's most recent answer to these two ideas came on March 11 from Fred C. Ikle, undersecretary of defense for policy, in testimony before a Senate subcommittee.
Mr. Ikle argued that the Carter administration made a significant effort to improve relations with Cuba. It opened an ''interests section'' in Havana, relaxed travel restrictions, and encouraged cultural exchanges.
According to Ikle, Fidel Castro's response was to increase the number of Cuban troops in Angola by more than 40 percent and to initiate ''a massive effort to subvert noncommunist regimes in Latin America.''
Ikle said that a ''political solution'' to the conflict in El Salvador, as seen by the guerrilla leadership, would mean a coalition government in which noncommunist members of the coalition would be ruthlessly eliminated.
The Reagan administration has said that it favors negotiations aimed at discussing conditions for the holding of elections in El Salvador. It accuses the guerrillas of advocating negotiations only in order to gain power that they would not be able to secure in elections.
Such ''alleged negotiations,'' said Ikle, would ''eliminate the possibility of free elections. . . .''