RIDGWAY'S PARATROOPERS; The American Airborne In World War II. By Clay Blair. Dial. 588 pp. $19.95.

THE PARACHUTE SOLDIER captured the imagination of the public in the Second World War, and has never since lost it, despite the deep-rooted skepticism of many professionals about the cost and effectiveness of airborne operations. Almost every army in the world today counts paratroop units among its elites. It is unlikely that there will ever again be massed parachute drops into action. But the spirit, the courage and dynamic inspired by airborne training are invaluable on any battlefield, as the British Parachute Regiment recently demonstrated in the Falklands.

In the Second World War, while America found great difficulty in forging infantry units of a quality to match those of Germany, the U.S. Airborne forces by 1945 had shown themselves among the finest fighting foot soldiers in the world. It cannot be a coincidence that the 82nd and 101st divisions produced such a glittering array of exceptional commanders at every level, among whom Gavin, Taylor and Ridgway were only the most celebrated. Matthew Ridgway, indeed, went on to perform a remarkable transformation of the American forces in Korea, at the brink of disaster. Clay Blair proposes to tell this story in a second volume of what one might call his military biography. But in this first volume, he deals exclusively with World War II, using Ridgway as a central figure around which to build a history of the inception and growth of the American airborne.

The Russian army startled the military world with their pioneering parachute exercises in the 1930s. But it was the Germans, using paratroops to such effect to spearhead their 1940 Blitzkriegs, whose achievements convinced the American and British armies that they must create powerful airborne forces. Ironically, the commitment of great resources to paratroops began in both countries just as Hitler, after Crete, had determined that the cost of massed parachute operations was too high to be borne. But this, of course, was unknown in London and Washington.

Omar Bradley was the first commander of the U.S. 82nd Airborne, but within a few months he was replaced by the austere, formidable Ridgway, a man of 46 when America entered the war. He approached parachuting with some trepidation -- not surprising when the transport pilots were learning their business from scratch, each man was still packing his own chute, and the army was riven by dissent about what the role of paratroops should be.

General Lesley J. McNair, like Eisenhower later, was skeptical about creating big formations for massed operations, and initially imposed a concept of divisional drops spearheaded by one parachute regiment, followed into action by two gliderborne regiments. This organization was later changed to reduce the gliderborne element after experience in action, when it was found that the esprit de corps and determination of the glider units fell some distance behind those of the parachutists, and that glider landings were fraught with difficulties of their own.

The great achievement of Ridgway and his colleagues through 1942 was to impose very high standards of fitness and training on their men, which in turn bred immense self confidence on the battlefield. Although a few Americans dropped into North Africa, the first major airborne operation took place in support of the 1943 Sicilian landings. It was a near-disaster: bad navigation and undisciplined flying scattered parachutists all over the island and the Mediterranean; poor liaison with the fleet resulted in horrifying casualties from friendly anti-aircraft fire. By Ridgway's reckoning, just 425 of 3,405 men of the 82nd were dropped near their objectives.

THE ARGUMENT about the proper employment of paratroops persisted into Italy. An alarming proposal for a drop on the edge of Rome was aborted only at the last moment, to Ridgway's huge relief. By the time final planning began for Overlord, the invasion of Northwest Europe, Blair writes that despite all the glamorous publicity, the truth was that so far airborne combat operations had been disappointing -- or worse. Yet amid the dismaying catalogue of difficulties revealed in landing paratroops, operations in North Africa and Italy had also revealed their extraordinary combat quality, the ability of even small numbers to cause important confusion behind the enemy's front. In Italy, generals had already begun to use the airborne to stiffen uncertain infantry formations. This was a practice that, in Northwest Europe, would become commonplace. Whatever the difficulties of deploying them into action, the Allies' parachute units were simply too good not to use.

George Marshall, in Washington, had always been a keen proponent of massed parachute operations. He had to be deflected by Eisenhower from promoting a deep drop behind the Normandy landings in the so-called Orleans Gap on D-Day. In the event, though the June 6 airborne landings were almost as chaotic as those in Sicily, the 82nd and 101st played a critical role in hampering the German response to the seaborne assault. Blair quotes some airborne men who believe that parachute landings behind Omaha beach could have prevented the near-catastrophe there. In any event, in the days following D-Day, at great cost the airborne played a critical role in leading the fight through the Cherbourg peninsula.

The quality of the divisions was never again in doubt. But the very proof of their excellence, when so many other infantry divisions were disappointing, caused commanders to keep them in action long after they expected relief to prepare for another drop. The 82nd suffered 5,245 casualties out of 12,000 men in Normandy; the 101st lost 4,670.

The American army has always adopted a ruthless attitude to failure among its leaders on the battlefield, and among the airborne, the readiness with which officers who were found wanting were replaced became a legend. Gavin sacked on the spot a glider battalion commander who declared himself to be feeling sick as his unit prepared to assault one of the Merderet causeways. Blair pulls no punches in naming the names of those who failed in action. His research corrects many of the omissions and misjudgments of earlier writers such as S.L.A. Marshall, and immediate postwar unit historians. After Normandy, Ridgway was promoted to overall command of the American XVIII Airborne Corps. It is the considered opinion of many historians today, including such British airborne survivors and authors as Major Geoffrey Powell, that if Ridgway rather than the British Frederick (Boy) Browning had been placed in operational command, disaster at Arnhem might have been averted. Overall responsibility for the Arnhem failure must be laid at the door of the Army Air Force's Brereton, who as commanding general bears chief blame for accepting the initial plan, the slow airlift, the failures of communications, and the decision to allow the British to land six miles from Arnhem Bridge, rather than tolerate the casualties of a direct drop.

The attack also took place amid a fatal background of conviction that the Germans were already beaten. The British First Airborne was a less impressive formation than the Sixth, which had fought so well in Normandy. Few of its units enjoyed the combat experience of the two American divisions. But the British planners felt that they could not reasonably award the most difficult objective to the Americans. Blair is far more frank about the successes and failures of the two American formations in Operation Market Garden than his British counterparts have been bout their own. It is enough here to say that the American airborne performed superbly. Only three months later, when pulled out of rest and refit for the Battle of the Bulge, they set the seal on their reputations as the American army's outstanding combat infantry units of World War II.

FOR WESTERN military planners, a conundrum emerged from the wartime experience: it was widely felt that too large resources had been lavished on airborne forces. The difficulties of concentrating aircraft and training crews to drop large bodies of men accurately remained chronic. Military parachuting remained a chancy business, in which the best- trained commanders and men were susceptible to jump injury.

Lightly-armed paratroops cut off from their own main front could never hold out or be resupplied for long against enemy armor. Yet, on the other hand, the paratroop spirit had proved of inimitable value in building a fighting shock force. Most armies today retain only a limited capability for massed parahute operations, but keep alive their airborne as an infantry elite.

It cannot be suggested that Clay Blair's book is elegantly written, and it has few pretensions to a wider understanding of the war than that from the immediate perspective of the U.S. airborne. Like so many books on World War II, it offers a critique of Allied battlefield successes and failures without troubling to assess closely the quantity and quality of opposition on each occasion, surely a vital factor in reaching an objective view. Blair is unashamedly on the inside looking out, rather than seeking a lofty oversight.

He does no more than scratch the surface of Ridgway's character, dealing overwhelmingly with what the general and his men did rather than seeking to probe his nature. Yet this is by far the most sensible study thus far of the American airborne, stripped of hyperbole and romance, engagingly honest about personalities, sound in placing the airborne in the wider context of the U.S. Army. It is a useful book rather than a dazzling one, but it underlines Matthew Ridgway's place as one of the outstanding American soldiers of the war.