A climate of fear has taken hold in this West African capital following the most recent executions of purported coup plotters and the accumulation of unchallenged power by Liberia's military head of state, Samuel K. Doe.

As has occurred with other African military governments that took power promising the restoration of political freedoms, Liberia's pro-American government has become an authoritarian regime that reacts with mounting harshness to the mildest criticism or suspicion of dissent.

Even the rudimentary trials that characterized the early weeks of Doe's 16-month-old government have been dropped in favor of hasty and secret trials before a special military tribunal. A student activist was recently put under a "banning" order similar to those used in South Africa and the country's only independent daily newspaper was shut down for 10 days when the publisher, his wife and nine of its staff were jailed for printing letters critical of the "banning."

Those leading Liberians who are willing to discuss the decline in respect for human rights here complain that the United States does not use the leverage it has with Doe's government to press for the respect of basic freedoms or steer this government toward returning power to the civilians. U.S. diplomats acknowledged that they are aware of these perceptions, but they added that they have less sway with the government here than their Liberian critics believe.

Since violently overthrowing the government headed by William R. Tolbert in April 1980, Doe's government has disclosed three alleged countercoup plots, revelations which have raised fears about the future reliability of Liberia's 5,000-member Army.

Significantly, the second countercoup plot followed the appointment on April 12 -- the first anniversary of Doe's coup -- of a committee to draft a constitution. Although no timetable has been set, the appointment of the commission was seen as the only hopeful sign of an eventual return to civilian government, a development the plotters apparently were hoping to thwart.

Doe has said several times that he and the ruling People's Redemption Council fully intend to return to the barracks "as soon as possible," but harsh measures taken by his government recently have led a large number of potential political leaders to fear that free elections will not be held soon.

Most of the Liberians interviewed during a recent visit who had critical comments to make about Doe's government declined to be identified out of fear of retribution, a new development in contemporary Liberia.

A prominent intellectual nervously insisted that he talk with a reporter in the seclusion of a hotel room. A high-level bureaucrat arranged for a daytime meeting at his home, not in his office. A previously plain-spoken government official declined the offer of a lunchtime conversation over the delicious Italian dishes he relishes at the popular Salvatore's restaurant. It was "too open," he said.

The Redemption Council, with Doe as chairman, included all 17 of the original band of noncommissioned Army officers and privates who overthrew Tolbert. The council also had 10 other soldiers, included so all of Liberia's 16 tribes would be represented. The council and Doe promised "dignity, equal opportunity, fair treatment and freedom of speech" to all Liberians in contrast to the deposed government, which had been dominated by descendents of the 19th century black Americans who founded the country.

Last year, nine Army officers accused of plotting to overthrow Doe were jailed on varying sentences. The second alleged plot, revealed in May, involved 13 soldiers who were tried and then secretly executed in early June. Three civilians were also arrested in connection with the May plot, brutally beaten, then released.

Student activist Commany Wesseh was banned in mid-June after a public disagreement with Doe. The banning led to a tense confrontation between university students and the military government. The tension escalated with the subsequent imprisonment of Wesseh and the staff of The Daily Observer, the country's only independent daily newspaper.

Before being jailed, Wesseh was banned from leaving the country, speaking to the press, interacting with any citizen, making public statements, dropped from membership on the constitutional commission and fired from his job with Liberia's electricity corporation. Similar banning restrictions are routinely issued by South Africa for, among other offenses, outspoken criticism of the government's system of racial segregation.

Wesseh's "antirevolutionary" sins, as outlined by Doe, were suggesting that Redemption Council members not drive around in big cars, not pay themselves large salaries and that they give the Liberian public a specific date for a return to civilian rule. Wesseh had also, according to Doe, charged that government officials were "accumulating wealth that should not be accumulated" and had disrupted a meeting that Doe was chairing with Liberians from northeastern Grand Gedeh County, both men's home area.

According to other Liberian sources, Wesseh was roundly applauded at the meeting for offering a development proposal that was preferred over one presented by Doe.

On his return from the Organization of African Unity summit in Kenya in July, Doe defused the growing confrontation between his government and university students by lifting his banning order and releasing Wesseh and The Daily Observer staff from jail. At the same time, however, Doe warned the students that any future confrontations would lead to "severe consequences."

Observer publisher Kenneth Y. Best said he has not been cowed by his 10 days in jail for printing high school students' letters critical of Doe's banning order.

"Too many of us are ready to fall on our faces at the slightest intimidation," said Best, who returned to Liberia a month after Doe's coup after working for seven years with the Kenya-based All Africa Council of Churches.

"Well, we're not prepared to do that at this stage," added Best, who began publishing the Observer in February.

The Redemption Council "is not open to dissent" because they equate criticism with domestic turmoil that preceded their overthrow of Tolbert's government, said University of Liberia Vice President Patrick Seyon. "They see criticism as opening up their downfall," he added.

Seyon, who was originally charged along with two other civilians in connection with the countercoup planned by the 13 soldiers executed in June, suffered kidney damage as a result of a three-day beating by soldiers but was released with the two others "for lack of evidence." A member of the constitutional commission, Seyon, like Wesseh, was a vocal critic of the Tolbert government.

Seyon said commission members believe they can come up with a draft constitution by next April. Asked if he felt the military government would honor its pledge to give control to civilians once a constitution is accepted, Seyon said, "I have been accused of being a perennial optimist, but I think they will fulfill their end once we've fulfilled ours."

The constitutional commission members are very worried, Seyon said, over whether the public will come forward to testify at public hearings after "the chilling effect of my arrest, Wesseh's arrest and the arrest of the Observer staff. There is still an uncertain climate here."

Since then, five Redemption Council members, all part of the original band of 17, were accused by Doe on Aug. 9 of plotting to assassinate him, tried in closed proceedings before the military tribunal over a three-day period and executed five days later.

The day of the executions, one knowledgeable Liberian said that the five represented the only "checks" on Doe's power and viewed the former master sergeant "as only the first among equals." Doe dropped his title of master sergeant in late July and is now referred to as commander-in-chief. At the same time, Doe militarized the entire government, drafting into the Army the 11 civilians of his 16-member Cabinet.

A Liberian source said after the latest executions, "Doe no longer has any opposition to what he says and does, and the Redemption Council no longer has any backbone."