Grenada has been more quiet than serene for the past couple of weeks, like a drunk sobering up after a bender. A kind of national hangover would be understandable: the tiny country has just endured four years of supercharged socialist revolution, a week of political chaos, a U.S. invasion, then a few giddy days simply feeling liberated. But what happens next is uncertain, and Grenadians and the American invaders both seem to be getting cranky. Military occupation, no matter how well intentioned, is never pleasant. "For the fact that the U.S. came, I say thanks," remarks Kevin Williams of Grand Roy (pop. 300). "But the quicker they get out, the better." On that point everyone seems to agree: last week the Reagan Administration promised that most of the 4,200 U.S. troops would be home before Christmas. But not all. "We will probably have a small presence well into 1984," says a Pentagon spokesman.

In the meantime, however, the troops cannot just sit back and sip rum punch: even when off duty, wandering the beaches in bikini swimming trunks, they carry M-16s. Last Thursday, in an almost slapstick incident, Americans came under fire. Before dawn on tiny Green Island, just off Grenada, a patrolling American literally stepped on a man, who leaped up, fired a few AK-47 rounds and scrambled into a waiting motorboat with three comrades. Two of the Americans were grazed. (The week had started with a wild rumor that Soviet commandos had put ashore. Their submarine turned out to be, in the words of a U.S. spokesman, "a whale and two intoxicated fishermen.")

Who are the lurking guerrillas and what is the point of their rear-guard sniping? Officially the only Cubans left on Grenada are an embassy official and his aide, but Major General Jack Farris, commander of the U.S. forces, believes no fewer than a dozen and as many as 30 holdouts are hiding in the bush. Another U.S. military official, however, thinks the stragglers want to make love, not war: the Cubans, he is convinced, are intent only on staying with their Grenadian girlfriends.

Almost four weeks after the invasion, -the other combat statistics also remained inexplicably unsettled. Only the 18 Grenadian civilians accidentally killed in a U.S. air attack, and the American casualties-18 killed, 113 wounded-are definite. Officials in Cuba and Grenada seem to agree that 25 Cubans and 21 Grenadian soldiers were killed. The Pentagon, meanwhile, counts 71 Cuban and more than 100 Grenadian dead.

Interrogations, conducted in assembly-line fashion, are nearly finished. Out of a population of 110,000, 2,200 Grenadians have been questioned at a jerrybuilt camp behind the nearly finished Point Salines airport on the island's southwestern tip. Most prisoners were kept in tents behind snarls of barbed wire, but some were obliged to crawl inside .8-ft. by 8-ft. wooden crates and spend 24 hours there. Finally, last week, Washington ordered the unseemly cages dismantled.

In at least one case, the U.S. forces claimed the solitary confinement was to protect a prisoner from fellow detainees: former Grenadian Justice Minister Kendrick Radix spent a night in one of the plywood boxes as prisoner No. 1,120. "The rain came in the night and I was drenched," complained the Irish-educated lawyer, still indignant. "I need a vacation." Indeed, in the span of three weeks, Radix, 41, has been imprisoned twice-first by the ad hoc Revolutionary Military Council (R.M.C.), the junta that overthrew and killed Prime Minister Maurice Bishop, then (for "spreading bad will among the people") by the U.S. forces that overthrew the R.M.C. Says Radix of Grenada's last month: "It was better theater than Shakespeare."

Truckloads of his countrymen, not yet charged with crimes, have been taken from the interrogation camp up to Richmond Hill prison, where they are being held for eventual trial. Among the 60 imprisoned at Richmond Hill is Bernard Coard, 39, Bishop's erstwhile deputy and the apparent mastermind of last month's coup. Because authorities are keeping Coard incommunicado, his brother Robert, director of Boston's antipoverty agency, has hired former U.S. Attorney General Ramsey Clark to intervene. "I just don't want Bernard to be railroaded," Robert Coard said. "All I'm saying to the American Government is let's play fair."

The U.S. Government has turned Bernard Coard into a poster boy. His photograph and those of fellow R.M.C. members, each defaced with a printed black X, are arrayed under a rather prejudicial pretrial headline: "These criminals attempted to sell Grenada out to the Communists. Now they have surrendered." The posters were produced by the Army's 100-member "psychological operations" group: some have been ripped down by islanders. Although the "psy ops" tacticians have wisely avoided attacks on the late and lo-ally lamented Prime Minister Bishop, their campaign may backfire anyway. A new broadside went up last weekend that truck Grenadians as an insult to their national pride and joy, the Cuban-built airport. Above pictures of Cuban weapons seized at Point Salines is the slogan ARE THESE THE TOOLS THAT BUILD CIVILIAN AIRPORTS? Army Jeeps fitted with loudspeakers cruise the island, blaring outdated propaganda ("Help send the Cubans back to Havana where they belong! Protect your hard-won freedom!"), and U.S. troops operate "Radio Spice Island," the only station permitted since the invasion.

Grenadians last week were dismayed to learn of what seemed a ham-fisted exercise of Yankee power: a unit of heavily armed U.S. troops closed and occupied a thriving Roman Catholic community house that a sergeant says had been "a center for Communist propaganda." Mab, a woman who worked at the facility, is upset. "It was a relief when the Americans first came," Mab says, "but this moving of us isn't so nice."

The occupation is not all rough spots, however. In St. George's, the capital, a sergeant was manning the Army's new claims office one day last week. "Come in tomorrow," he told a taxi driver whose cab had been commandeered and wrecked by U.S. troops. "Washington has okayed the funds." The U.S. Agency for International Development, already funneling $3.5 million in reconstruction funds, has proposed sending another $30 million to Grenada in the coming year, equivalent to a third of the island's annual G.N.P.

Some generosity is necessary. The invasion has ruined tourism for this season at least. Last year Grenada got about $40 million in economic aid from Communist countries, which certainly won't continue. The popular Socialist government was able to give Grand Roy residents free cooking oil and powdered milk once a month. "The Cubans made a positive image here," says William Wheeler, AID chief in the Caribbean, "with education, with medical treatment and with the airport." All 30 Cuban teachers and two dozen doctors on the island have been deported. This week 26 replacement teachers will arrive from Barbados. There are hastily contrived public jobs, mostly makework for 1,600 suddenly unemployed Grenadian soldiers. The ex-soldiers, admits Ted Morse, an AID official, "are making square potholes out of round potholes."

N ow that U.S. combat troops are committed to leaving in a month, the Grenadians must all the more urgently refashion a political order. Last week, as General Farris stood by with his holstered pistol, five members of Governor-General Sir Paul Scoon's nine-member "advisory council" were installed. They are to run the country until popular elections are held, probably next spring or summer.

Despite some disillusion with the Americans among the islanders, international censure of the U.S. has faded fast. At the Organization of American States' meeting last week in Washington, not one delegate suggested that the U.S. should be formally criticized for the invasion.

Even Fidel Castro, in a speech last week, practically made excuses for the U.S. With a million cheering Cubans crowded into the Plaza de la Revolución, Castro gave his obligatory harangue of the U.S., but he also powerfully condemned Grenada's Octoberists for last month's coup. "Coard's group," Castro said, was a "morally indefensible" regime that had "destroyed the revolution and opened the door to imperialist aggression."

The imperialist aggressors, at least, are spending their money in St. George's crowded restaurants, especially Mama's and the Red Crab. The island's electricity is back on. Conch fishermen are working, and the banana-boat traffic has resumed. But with roadblocks up, public meetings banned and M-16s as commonplace as homespun fishing spears, there is still some trouble in paradise.

-By Kurt Andersen. Reported by Bernard Diederich/St George's and ChristopherRedman/Washington