"EVEN NOW that it is all over, it is hard to grasp the enormity of what happened," the editors of the Insight special reporting team of The Sunday Times of London note in the introduction to their impressively detailed and thoughtful instant history of the war between Britain and Argentina over the Falkland Islands. "In the last quarter of the twentieth century, Great Britain went to war, sending a naval task force of one hundred ships eight thousand miles to the South Atlantic, to engage an enemy of the last outpost of a forgotten empire."

It was anachronistic and yet the first truly modern war. It intermingled stubborn Victorian defense of honor, World War I-vintage foot soldiering and Star Wars combat with space-age missiles. It became a laboratory for arms manufacturers whose weapons were tested in combat for the first time; some didn't even wait for the war to end before advertising their successes as the death toll mounted from sinking ships and exploding aircraft.

Although there was relatively little else at stake for anyone besides the two combatants, the Falklands war attracted as much media attention as the Israeli invasion of Lebanon and more than the bloodier war between Iran and Iraq. Yet most of that coverage was sketchy at best. Live television reports were made impossible, correspondents accompanying the British forces were strictly censored, and much of the information from governments in both London and Buenos Aires was fragmentary or false.

Publishers seeking to cash in on satisfying any postwar appetite for more facts have been rushing out books here and in Britain. Two of the first three in American bookstores, however, fill little of the void.

One, Struggle for the Falkland Islands, deceptively titled to sound more timely, is a Yale University Press reprint of a 1927 historical analysis of competing English, French, Spanish and Argentinian claims to the Falklands from their discovery in the 16th century to their reoccupation by the British in 1833. The late Julius Goebel, who was a law professor at Yale and Columbia, concluded that Argentina had a much better claim than Britain to the Falklands, but this has now been mooted for everyone but diplomats and scholars by Britain's unconditional military victory last summer. And Goebel is contradicted in the book's introduction by a British authority on Spanish history, J.C.J. Metford, leaving the Yale University Press safely on both sides of the question.

The other, Fight for the Falklands, is a blatantly British-biased, jingoistic, badly written propaganda tract obviously based on press clippings and statements from Her Majesty's Government. It should be an embarrassment to St. Martin's Press, which describes author John Laffin as a "noted British military historian" with "an insider's knowledge of the Thatcher government," both of which are contradicted by this thin volume.

But a third book, War in the Falklands, does fill in many of the gaps in our knowledge. It provides significant new details and insights about the military action, gleaned from painstaking debriefings of British officers, including many interviewed during their slow return to Britain by sea from the Falklands, and the most complete accounts yet from Argentine officials.

In particular, The Sunday Times team documents how close the adventure in the frigid South Atlantic came to being a disaster for Britain, even before Argentine bombs rained down on British ships and failed to cause crippling casualties only because many of them never exploded. British combat preparations were hampered by rivalries among military planners, and initial attempts to land commandos secretly behind enemy lines were plagued by accidents and equipment failures rivaling the disastrous U. S. attempt to rescue the hostages held in the American embassy in Iran.

Helicopter crashes scuttled attempts by Special Air Services commandos to land onto a glacier on frozen South Georgia Island and engine trouble stalled seaward approaches by the Royal Marines' Special Boat Squadron. Only dramatic rescues prevented large losses of life in these misadventures, none of which were reported back home where it was assumed that British commandos were secretly swarming over South Georgia and the Falklands.

South Georgia was finally retaken in a hasty unplanned gamble by outnumbered British forces after a Royal Navy combat helicopter discovered and disabled an Argentine submarine resupplying the enemy garrison on the island. It was only the first of many battles that would end with victorious British troops amazed by how badly outnumbered they had been. The land war was largely decided by the Argentine conscripts' lack of fighting spirit after outposts manned by tougher troops were overrun by the British.

The book's detailed reconstruction of diplomatic efforts to avert war also shed new light on how close various mediators came to successfully negotiating a settlement between the British and Argentine governments, only to be thwarted by the resistance of hard-liners inside Argentina's military junta and Britain's sinking of the Argentine cruiser, General Belgrano. While confirming that Prime Minister Margaret Thatcher's "war cabinet" authorized the attack on the cruiser even though it was outside the British-designated war zone at the time, the authors are unable to decide whether its sinking and the breakdown of negotiations for a settlement requiring uncomfortable compromises for Thatcher were anything more than coincidental.

Written before the British government began an exhaustive inquiry into the war and its origins, the book offers no new conclusions about this or other major decisions and miscalculations made on both the British and Argentine sides. But, besides being a readable, well- paced narrative of the war, it does a better job than might be expected so soon after the event in providing basic information needed to judge important revelations the future inevitably holds.