Looking beyond the immediate action on Grenada, critics are asking half a dozen key questions that are likely to be debated for months. President Reagan gave the safety of the Americans on the tiny Caribbean island as the main reason for what he has called a rescue operation.
Some of the questions under debate:
Were the Americans on the island in enough danger to justify the use of armed force to evacuate them?
Many of the first students to come out of Grenada certainly thought they were in danger. But many also admitted they were isolated on their campuses, not knowing much about what was happening elsewhere on the island except by way of the government-run Radio Free Grenada.
Reagan administration officials have yet to provide concrete evidence that members of the leftist-led military council, ostensibly ruling Grenada at the time, had given any thought to taking Americans hostage. But the officials argue that the situation was not only uncertain but chaotic, that council members had used violence against their domestic opponents, and that the example of the Iranian hostage crisis was in the back of their minds.
Could the United States have used negotiation to get the Americans out?
The Grenadian military council sent a cable to the US Embassy in Barbados informing American diplomats that the safety of US citizens was assured and that Americans would be allowed to leave the island. A White House spokesman said the administration distrusted the assurances because of the apparent instability of the ruling group on the island. A group of Americans did get out on one flight on Oct. 24, shortly before the invasion. But other charter flights were not allowed to land at the Grenada airport. There is still considerable confusion over the reasons for this.
President Reagan gave as a second reason for the Grenada operation a request from East Caribbean nations, which felt threatened by a military buildup on Grenada. Were those nations under any real threat?
These small island nations have armed forces that, even when combined, are no match for those that had been built up on Grenada. The islands' leaders suspected that Grenada was training insurgents. Those same leaders also observed the Cuban presence on Grenada and the construction of a new airport, which, once completed, would be capable of accommodating high-performance jet fighter-bombers.
But much remains to be learned about Cuban intentions. It is now clear that before the invasion, American intelligence on Grenada was far from complete. Some of the Cuban and Grenadian military buildup on the island may have been related to fear of an American invasion. News correspondents on the island say that many of the arms stored there are less than modern.
Speaking in the Reagan administration's favor, however, is Alistair Hughes, a highly respected Grenadian journalist who had been placed under detention by the island's military council. After being freed, Mr. Hughes said that the US troops had come just in time to prevent a further deterioration in the situation.
President Reagan gave as one reason for the Grenada action a need to restore order and democratic institutions on the island. Are those aims feasible?
An American admiral said that restoring order would require identifying hard-liners from the now-ousted Grenadian military regime. That could require an American military presence on the island for some time to come. But armed resistance to the occupying force appears to have dramatically diminished over the last day or so. A semblance of order and normalcy is returning to the main towns.
The US would like to bring in a peacekeeping force, which could consist of troops from the Commonwealth nations and neighboring Caribbean states. This would allow US forces to leave as soon as possible.
US State Department experts are convinced that democratic institutions can be created, permitting free and fair elections. Grenada's governor general, Sir Paul Scoon, gave a radio address on Sunday saying he will appoint an interim administration within days. Sir Paul called for an early return to full constitutional government through elections. One thing that may work in favor of Sir Paul and his US and Caribbean supporters is the welcome that many Grenadians seem to be giving to the invasion forces. But press reporting on this aspect of the invasion is still fragmentary. It will take a while longer to determine how widespread the revulsion was against the now-ousted military regime and its leftist ideologues.
How severe was the damage done to US relations with key European and Latin American allies who are now protesting the invasion?
State Department officials argue that the damage done was much less severe than might be evident from public statements made by those nations. One official said that the US was informed by diplomats from a number of key Latin American nations that their governments actually welcomed the invasion but could not state so publicly.
UN Ambassador Jeane J. Kirkpatrick has argued that many Frenchmen see the US action in Grenada as being at least as defensible as France's recent deployment of troops to protect Chad. Undersecretary of State Lawrence S. Eagleburger says it is also important to note that when the UN Security Council voted against the US, the British abstained, thus moving ''in the direction of at least trying to indicate some support'' for the US.
But critics in Western Europe who feared that President Reagan was trigger happy will now feel that their suspicions have been confirmed. They may now protest all the more vigorously against the planned emplacement of new US missiles on European soil.
Does the invasion of Grenada mean that the US will attack Nicaragua?
Deputy Secretary of State Kenneth Dam gives an unqualified ''no'' in response to this question. Mr. Dam notes that the US does not fear for the lives of American citizens in Nicaragua.
No request has come from any regional organization for such action, he says.
The size of Nicaragua compared with that of tiny Grenada would make an invasion of Nicaragua a much more costly operation.
But some individuals inside the Reagan administration are reported to like the idea of making Grenada a ''dress rehearsal'' for Nicaragua. However, State Department officials for the most part oppose this idea.