The war on drugs is overwhelming a criminal justice system whose greatest problem is lack of resources, not legal protections afforded criminal suspects, a two-year American Bar Association study concludes.

"The entire system is starved: police, prosecution, criminal defense, courts and corrections," says the report by an ABA committee. "As currently funded, the criminal justice system cannot provide the quality of justice that the public legitimately expects and that the people working within the system wish to deliver."Less than 3 percent of all government spending in the United States went to support civil and criminal justice activities in fiscal 1985, a previously released federal study has shown.

Those already thin resources are being overwhelmed by a massive - but largely unsuccessful - battle against illegal drugs, the ABA panel concluded.

It said that while courts are increasingly clogged, the drug problem "is growing worse, and . . . law enforcement has been unable to control" it.

The ABA study noted political disputes about the Miranda decision but found relatively few problems in the field related to it. That decision, issued in 1966 by the Supreme Court, said police must warn suspects of their right to remain silent and to consult with a lawyer before any questioning takes place.

While the Miranda decision "has sparked heated controversy on a political level, the restrictions it imposes on custodial interrogation of suspects are not considered troublesome by either police or prosecutors," the panel said.

Eighty-seven percent of prosecutors surveyed for the study said no more than 5 percent of their cases were dismissed because of problems involving the Miranda requirements.

The exclusionary rule - under which evidence obtained illegally by police may not be used in court - also has caused few major problems, the study concluded. Some police officials, in fact, told the panel that the demands of the exclusionary rule have promoted professionalism in the nation's police departments.

Most prosecutors put the number of cases dismissed because of the exclusionary rule at 5 percent or less, while three-quarters of the judges and defense lawyers polled said suppression motions succeed just 10 percent or less of the time.

The study was based on testimony from the legal community and a national telephone survey of police, prosecutors, defense attorneys and judges. It was compiled by a panel chaired by Samuel Dash, former chief counsel to the Senate Watergate Committee and a Georgetown University law professor.

The study said efforts to bring the nation's drug problem under control are swamping the criminal justice system.

"Police, prosecutors and judges told the committee that they have been unsuccessful in making a significant impact on the importation, sale and use of illegal drugs, despite devoting much of their resources to the arrest, prosecution and trial of drug offenders," the panel reported.

"These extraordinary efforts have instead distorted and overwhelmed the criminal justice system, crowding dockets and jails, and diluting law enforcement and judicial efforts to deal with other major criminal cases."

The panel recommended that the ABA set up a special commission to study and re-evaluate national, state and local strategies in dealing with the drug problem and to educate the public and lawmakers as well as government policymakers.