THE ROLE of the U.S. press in the Vietnam war, the subject of persistent controversy for more than a decade, raises important issues for journalism, government and American society as a whole. Here is a first-rate book which throws new light on the topic rather than generating more passion and which is based on scholarly analysis of what actually was published and broadcast, judged in the context of historical events.

As author Daniel C. Hallin points out, defeat in Vietnam has given rise to the widespread view, accepted both by satisfied journalists and their embittered detractors, that an independent, skeptical news media clashed with government policy in a way that shaped the outcome of the war. Moreover, the consensus is that television's role in bringing the battlefield into American living rooms reduced American tolerance for combat and thus inaugurated a new era in which wars must be won quickly and outside camera range or not at all.

Hallin, a political science professor at the University of California, San Diego, puts a crimp in both of those widely-held ideas. His well-documented analysis, which seems much closer to the truth than most of what has been written on the subject in the past, raises new questions about the roles of the printed press and television even while refuting existing myths. His book can be said to be the first serious revisionist history of the role of the press in Vietnam. It will not comfort either reporters or officials in the continuing battle over the flow of information but should make all sides reconsider some key questions.

Hallin develops his case out of two extended studies: of the complete record of New York Times coverage from 1961 through mid-1965, the formative period of U.S. escalation, and of television evening news coverage from mid-1965 to the ceasefire in 1973. Comparing the Times accounts with the documentary evidence of what was actually going on, as later revealed through the Pentagon Papers, memoirs and other sources, Hallin shows that the Times coverage of 1961-65 was a monument to the ability of the Kennedy and Johnson administrations to control and manipulate the news about Vietnam.

From the 1961 decision to send U.S. troops to Vietnam (which was misreported as a decison not to do so) through the 1964 Tonkin Gulf episode (which was not the surprise that the Johnson administration suggested) to 1965 decisions to undertake sustained U.S. bombing of North Vietnam (portrayed at the time as limited instances of retaliation), the reporters at the Times were well behind the curve because the government lied or dissembled and the press lacked independent knowledge or credible sources to the contrary.

A notable exception in the generally dismal picture of Times coverage -- which was selected because it was the most extensive and probably the best in the U.S. press at the time -- were some of the stories submitted by military correspondent Hanson W. Baldwin. He was right on the mark with inside information on several occasions, but his stories were given less prominence than those of White House, State Department and Saigon reporters, and were often discounted because Baldwin was considered so close to the military high command and a hawk on the war.

After 1965 and especially after the Tet Offensive of 1968, most of the print press, including the Times, became more skeptical and adversarial in its coverage. An important part of the reason, Hallin points out, is that dissent broke out within the U.S. government, giving rise to alternate versions of events available from official sources both here and in Saigon.

Hallin doesn't make much of a point of it, but the fury of the press about being misled in 1961-65 about Vietnam was part of the reason for the later trend toward more adversarial reporting. The shift in newspaper and magazine reporting starting in 1966 and 1967 is mentioned, but not documented here. To do so would have required an even more massive research effort and an even more ambitious book, but it would have been worthwhile.

AS FOR television, Hallin begins with August, 1965, because that was the starting date of the Pentagon's archive of television coverage, predating by three years the Vanderbilt Television News Archive, which since has become the standard source for scholars. Hallin's data and conclusions are drawn from a content analysis of a random sample of eight to 12 network evening news programs per month, 779 in all, throughout the 1965-73 period.

Despite some spectacular examples to the contrary, such as Morley Safer's famous 1965 report on the Zippo lighter torching of the village of Cam Ne, Hallin found that the overwhelming flow of television reporting prior to 1968 was "strongly supportive" of American actions. Most of the battle coverage, he reports, was of American troops in action, essentially through their eyes.

In one of several sections of analysis which add depth to the book, Hallin describes television as "a more ideological medium than the newspaper" with a tendency "to simplify and unify" as well as to "moralize" within a relatively narrow spectrum of permissible deviation from officially-sanctioned views.

Television was slower than than the print press in 1965-67 to depart from the official U.S. perspective, Hallin asserts, but changed to some degree after Tet, 1968, as the broad national consensus and many government policies turned against the war. Even then, Hallin concludes, television gave short shrift to the diplomatic positions of the North Vietnamese or to the actual arguments, as opposed to the violence and drama, of the domestic anti-war movement.

What is remarkable, Hallin concludes, is that the press and public went along with the war as long as they did. At least a year before Walter Cronkite called Vietnam a "bloody stalemate" and urged negotiations, Hallin points out, Secretary of Defense Robert S. McNamara had reached essentially the same conclusion.

On the whole Hallin finds the establishment press in the Vietnam War less an agent of dissent than an agent of government policy and, later, of contending viewpoints within the U.S. establishment. One can argue about how much has changed since then, though it seems undeniable that the coming of op-ed pages and television programs such as Nightline and McNeil-Lehrer have allowed expression of a wider range of views.

In sometimes arcane and academic language, Hallin points out what even beginning reporters know instinctively: that journalists are limited by their sources and of the worldviews of editors, colleagues and consumers. The tragedy of Vietnam loosened the hinges of the press-government connection, but it did not change the basic realities.