Detente came to Prince George's County two years ago, when educators and prominent black residents set aside an ugly history of confrontation over busing to test a voluntary school desegregation plan. Today, charges of bad faith, greed and broken promises have threatened the peace.

In the first major dispute since the court-ordered desegregation plan was implemented in the fall of 1985, prominent blacks and the Board of Education and Superintendent John A. Murphy have headed back to court.

This week, the county NAACP and school officials appeared before a federal judge who has been asked by black leaders to rule on whether school authorities have reneged on a promise to reduce class sizes and provide more teachers and resources at 14 predominantly black compensatory schools.

Also known as Milliken schools, they are among a small group in the nation that, in line with a U.S. Supreme Court ruling, receives special staff and materials because they are declared too difficult to desegregate. They are one of the first court-sanctioned alternatives to busing for desegregation purposes.

The concept is based on the Milliken v. Bradley (II) Supreme Court decision in 1977 upholding the practice of maintaining one-race schools if increased resources are targeted for their pupils. But the Supreme Court's ruling, an affirmation of a lower court decision, left individual school districts and their communities to negotiate the level and kind of compensation.

The legal battle in Prince George's comes at a time when the county is enjoying a wave of good publicity and growth, much of it linked to the new academic progress and enthusiasm in the once-beleaguered school system, the area's second largest.

"It's the first fallout since the desegregation plan was introduced," says school board member Sarah Johnson.

At the core of the Prince George's dispute is the seemingly simple issue of class sizes and whether the county has kept its end of a bargain to have one teacher per 20 pupils in classes in the Milliken schools. Now that simple disagreement is evolving into a test of wills, a battle of the symbolic versus the pragmatic.

School officials, facing a $16 million budget cut, say reducing class sizes to the extent outlined in an agreement with the NAACP would pose severe logistical problems in already crowded schools and cost nearly $1 million.

"We're responsible for giving the best we can with the dollars that are available," Murphy said in a recent interview, noting that 61 percent of the system's students are black. "We can't be greedy as we deal with these issues."

To others, the issue is also symbolic -- a matter of weighing the preservation of the constitutional rights of about 6,000 black children against the practical operation of a system with 102,000 pupils. To begin making concessions, black leaders maintain, threatens the future of the Milliken schools and, perhaps more important, the integrity of the desegregation plan.

"We want a desegregation plan that's lasting," said Alvin Thornton, chairman of a countywide committee monitoring the plan.

As in almost any education program, the degree of success or failure in the Milliken schools varies. In the two years since their introduction, standardized test scores at some schools have risen as much as 25 percentile points, while other schools have made little progress.

Superintendent Murphy has pointed to the accomplishments at the Milliken schools as an indicator of his commitment to them. "I think I have sufficient objective data that we're operating in good faith," he said.

But parents of children attending John Bayne Elementary in Capitol Heights, for example, are not convinced. They have complained that while class sizes averaged 22 pupils this year, kindergarten classes peaked with 28 pupils. They also have complained that five of the 30 computers that the school received in the first year of the Milliken program were withdrawn last fall along with some state-funded teachers.

"Don't tell me he's supposed to have this and then put something else in and {tell me} I'm not supposed to complain," said Catherine Wade, whose son attends John Bayne.

Beyond the experiences at individual schools, the dispute has brought to light criticisms that some of the highly touted components of the Milliken program are more superficial than substantive. It also has brought to the surface long-held concerns that the Milliken schools are being shortchanged in favor of the popular and successful magnet school program.

Magnet schools attempt to achieve a better balance in integration by offering special programs that generally attract white pupils to predominantly minority schools.

The Prince George's experience with Milliken schools reflects questions now being raised nationally by educators and civil rights experts examining the legal, social and practical implications of legally condoned segregated schools.

Among the questions being asked: What and how much should the schools receive to compensate for the inequities of segregation? Should new resources replace existing educational programs, or add to them? Should the emphasis be on new books and computers in place of a well-defined educational program?

Prince George's is the only school district in the Washington area -- and one of a few nationwide -- to introduce the Milliken concept as part of an overall desegregation plan.

It did so two years ago when black parents and educators agreed that the inner-Beltway locations of some schools -- such as District Heights, Chillum and Hillcrest Heights elementaries -- made them too difficult to desegregate because of their distances from predominantly white communities. In a county that covers 487 square miles, both blacks and whites opposed the long bus trips to or from communities close to the District line.

As part of an agreement stemming from a longstanding desegregation suit against the school system, both sides drew up a plan to pour new teachers and resources into the designated Milliken schools.

In the fall, the county plans to spend $5 million of its $425 million budget for materials and supplies for the 14 elementary schools and one senior high school. The program's per-pupil cost this year was $415 more than the county's average $3,624 per-pupil spending, although $73 less than comparable spending for the magnet programs.

The pledge specifically includes full-time guidance counselors and librarians, cultural programs, special mathematics and language teachers, computer laboratories and after-school tutoring. The school system also introduced into the Milliken schools a new technique for motivating pupils based on high expectations and increased parental involvement, developed by Yale psychiatrist James Comer.

Basically, most of those promises have been fulfilled. But different interpretations about the degree and level of new resources have existed almost from the beginning. Specifically, the agreement between the county and NAACP sets as a goal in the Milliken schools a "ratio of regular classroom teachers" to pupils of 1 to 20.

Last fall, in the second year of the program, school officials factored in resource teachers at each school when computing class sizes at the compensatory schools. Resource teachers do not have classrooms; rather, they assist regular classroom teachers by working with small groups of children. Most compensatory schools have two resource teachers.

In most of the Milliken schools the actual class size hovers around 23 pupils, according to school enrollment data.

After factoring in the resource teachers, however, the school system officially reported the average Milliken school class size as 19 pupils. Countywide, there is an average of 27 pupils in elementary school classes.

Some black activists and parents also have complained that Murphy ordered 21 teachers funded through a federal and state program withdrawn from 11 of the Milliken schools. The teachers, who are generally assigned to those schools with the highest number of low-income pupils, were reassigned to other schools that had fewer low-income pupils but still qualified for the extra staffing.

School officials said their decision to use resource teachers in determining class size adheres to the court agreement.

School officials said they decided to transfer some state and federally funded teachers to other schools -- some in predominantly black schools, others in largely affluent white communities -- because in many cases they duplicated the work of the new resource teachers.

"It became a management decision where we had too many folks in the building. People were falling all over each other," according to school board Chairman Thomas R. Hendershot.

Complicating the current controversy is that most of the county's 170 schools have few of the resources -- such as computer labs and full-time librarians and counselors -- given to the Milliken and magnet schools, which enroll fewer than one-third of the pupils in the county. But parents of Milliken pupils say that such comparisons are inappropriate because the extra resources for their schools are the product of a court agreement.

"If we're not going to be any different," said Wade, "then don't segregate us."