More than two decades after the introduction of an all-volunteer force, the military continues to fall "significantly short" of meeting service members' expectations that they and their families will enjoy a reasonable lifestyle.

Men and women in the military feel overworked and underpaid, complain that they lack the resources to carry out their missions and say they lack confidence in their leaders, according to an extensive private study of attitudes within the armed forces to be released today.

But the study said that men and women in uniform continue to hold a strong sense of duty and sacrifice.

The Defense Department has recently undertaken to improve pay, health care and housing, but other sources of lifestyle stress may be more difficult to remedy.

The study by the Center for Strategic and International Studies (CSIS), a conservative think tank, found that the two-career family, a staple of civilian life, is now increasingly common in the military as well and poses inherent conflicts with the need to frequently transfer personnel or send them off on long deployments far away.

The study, "American Military Culture in the 21st Century," is based on a survey of 12,000 personnel around the world, 125 focus groups with officers and noncommissioned officers and analysis of personnel surveys conducted by the military services. It is the broadest examination in recent years of how the military sees itself. The authors, all former senior military or civilian defense officials, found cause for concern in the attitudes they uncovered.

"America's military is facing potentially serious rifts in the fabric of its culture, with attending damage to future operational effectiveness," the study concluded.

Although military personnel are better off than in "the dark days of the Vietnam War" or in the 1970s, when defense spending was drastically reduced, "there is little doubt in the minds of the study participants that conditions within the armed forces are far less favorable than they were a decade ago," said the study.

Military service by homosexuals is not a preoccupation within the armed forces, despite the intensity of political debate over the issue, the study found. During the 125 focus groups, "the issue of gays in uniform was hardly ever flagged as a key concern by a man or woman in uniform," the study said.

External pressures, such as the draw-down of military forces following the Cold War, the steady pace of humanitarian and peacekeeping operations and economic competition with a booming civilian labor market, all contribute to morale and readiness problems, the study found. Senior military and Clinton administration officials and congressional leaders have raised similar concerns and responded with pay raises, budget increases and policy reviews.

Since the draft ended in 1973, the percentage of married personnel has risen from 36 percent to 56 percent. While the preponderance of married service members brings a greater maturity to the armed forces, it also "puts an unprecedented emphasis on quality of life issues," the survey found.

Of the 99 questions on the survey, respondents were least likely to agree that they were paid fairly and given enough time to deal with home life issues.

The services have recognized some of the problems and tried to deal with them. The Navy, for example, tries to ensure that sailors spend no more than six months at a time at sea, and that every cruise is preceded and followed by lengthy time in home port.

At the same time that personnel challenges have grown more complex, military life has grown more demanding. The rate of overseas deployments for the armed forces increased by more than 300 percent over the last decade, and the CSIS study blames the military itself for failing to take account of these developments.

"Simply put, the leadership of the Armed Forces has not yet adjusted to the reality that there are insufficient operating resources and personnel to match missions," the study concluded.

"We found one basket of issues that relate to policy and resources and that can be addressed by the nation's civilian leaders, but there are another category of difficulties that only the military itself can address and those center on leadership," said Joseph J. Collins, a retired Army colonel and West Point instructor who directed the project.

"The most powerful and direct influence on organizational climate, eventually on culture, comes from within the officer corps of the armed forces," the study found.

But only slightly more than a third of the service members surveyed expressed agreement with the statement "when my service's senior leaders say something, you can believe it is true," and only the same fraction agreed that "an atmosphere of trust exists between leaders and their subordinates."

While many corporations have shifted to decentralized management structures that encourage individual initiative, the CSIS study found that the armed forces have made uneven progress in this area. "Advanced communications technology, such as video teleconferencing and the internet, has magnified a tendency toward micro-management in military organizations," said the study, which reported complaints from junior officers over "command by e-mail."

Still, the survey found widespread agreement on basic military values. The survey question that drew the largest number of affirmative responses was one that asked whether respondents agreed or disagreed with the statement: "I am proud to serve in America's armed forces." Similarly, respondents strongly agreed that they had "a deep personal commitment" to military service and would put their lives on the line for a mission.

"Despite obvious pressures on today's military, men and women in uniform have embraced traditional military values," the study said, but that commitment "does not translate automatically into high morale or satisfaction with military life."