THE MOVEMENT of the 1940 armies in Blitzkrieg and Dunkirk is from the interior of Europe toward the coast, and not in the opposite direction described 2,300 years earlier by Xenophon's Anabasis. Yet such are the iron whims of all military historians that it sometimes seems to a reader of these two new books that the compass direction is the only thing they have in common. They don't appear to be about the same war.

Nicholas Harman, a British journalist who was 7 at the time of Dunkirk, is no stranger to war. He was badly wounded while leading a heroic night patrol into a Korean ambush in 1952 and he has written an exciting and meticulously researched account of Dunkirk. He claims that the only "miracle" was the way the Churchill propagana machine transformed an ignominious rout of the British Expeditionary Force (BEF), which escaped alive only by double-crossing its valorous feat of heroism -- a "patriotic myth," an emotional shot in the arm for the beleaguered English.

Len Deighton, the master spy-novelist who seems to be working his way through World War II as an historian (Bomber and Fighter were about those RAF wartime commands) has done his homework just as thoroughly, often with Harman's references. He comes up with the conclusion that the British Army under Viscount Gort did as well as it could, sometimes brilliantly, against Heinz Guderian's terrifying new technique of blitzkrieg, or lightning war (the term is variously attributed to Hitler and Time magazine and in any case is probably "not of German origin"), that the Belgians caved in at a crucial juncture, that the Frech were superior to the Wehrmacht in tanks, fighters and bombers but collapsed absymally from fear, indecision and wretched leadership by elderly dummies and that the evacuation of over 300,000 Allied troops was indeed a miracle of luck and heroic improvisation. He makes no mention of British perfidy, but rather inclines to the idea that Gort's "hunch" in plugging up the gap caused by the Belgian surrender was a bit of genius that saved the day.

Harman's theory is that some kind of "Dunkirk" was uppermost in British thought from the start of the war -- or at least from the end of the "sitzkrieg" or phony war that followed the fall of Poland in 1939. They had no intention of wallowing again in the mud of Flanders as they had in World War I. Despite Churchill's desperate attempts to con the French into staying in the war, Harman elaborates French-British hostility in a way that makes Gulliver's rival Lilliput and Blefuscu seem like old wartime cronies. On crucial May 21, with the Germans near the channel, French General Weygand landed at an RAF airport, on his way to a meeting at Ypres with King Leopold of Belgium and Lord Gort, to be told by a French private, in sole command, that "They've all pissed off!" When Weygand finally got to Ypres, Gort didn't turn up until he'd left. "Then and later," says Harman, "the French believed that Gort had deliberately missed this vital conference . . . . For four crucial days neither the alliance in the North nor the largest French army within it had a fulltime commander."

To Harman the British fear of losing the secrets of the new radar to spies in France was "why the RAF was carefully held back from the battle over the Continent," and that "the greatest danger run by the British Army in France during its long wait for the action" was VD. Whatever preparations Britain made for Operation Dynamo, code name for the vast cross-channel evacuation, no mention of it was leaked to the French, and until the very last moment the French, according to Harmna's readings and personal interviews, were under the misapprehension that both they and British would fight to the last man. "Do the Belgiums really think us awful dirty dog?" Lord Gort is reported to have said quietly to a British naval officer after a meeting with Leopole on May 21. And despite written orders that, finally, French and British troops were to be evacuated in equal numbers, the orders went largely igonored.

Deighton paints no such dismal picture of perfidious Albion but he does explode his share of myths. Dunkirk is only the curtain line in his story of the rise of Hitler and his highly-detailed treatise on blitzkrieg -- the invention and short, happy life of a new military device. Along the way he points out that:

Poland did not fall to blitzkrieg so much as a speedy improvisation of classic Prussian encirclements known since Bismark. Proper blitzkrieg, "the swift, sudden offensive by combined air and land forces," was ideally and solely suited to the network of roads in Western Europe. It was never really used earlier and would never happen again.

The Reichstag fire, Deighton thinks it "virtiually certain, was not set by the Nazis but was Hitler's lucky chance to take over in 1933. He gives a detailed account of Hitler's "night of the long knives" and the neutralization of Ernst Rohm and his radically dangerous SA army.

Chamberlain's default at Munich presented an impoverished Hitler with at least one-third of his armor in Czech tanks.

The French had fully adequate antitank and antiaircraft equipment because they'd been selling them for export for years.

Blitzkreig was "more fatal to morale than to men." The idea of the armored-battle-wagon and the diving-battle-flying machine was far more effective than their potency -- together they caused only 5 percent casualties. e

The capable British quartermaster corps may have done as much to save the BEF as anything by quicly moving huge supply dumps north into the cutt-off sector.

The biggest myth of all is that the might of German Panzers and Stukas were faced by planeless, tankless, cannonless riflemen. The allies had more and better tanks, planes and guns (though not the redoubtable German 88).

It was hopeless slowness and ineptitude of the French generals commanding the movements of the 1st and 3rd French armored divisions (Deighton singles out Huntziger as the worst) that kept the fragile, overextended German thrust to the Channel from being wiped out and the course of history materially changed.

The last-minute respite given the BEF at Dunkirk (and here Deighton and Harman seem to agree) was not a merciful gesture by Hitler, but was brought on by real exhaustion and an effort to regroup for the more important drive south to Paris. "The defeat of the Allies was a failure of communications and command. Time was the most vital factor but it was squandered . . . The German drive to the sea had contiued virtiually without opposition while thousands of French aircraft stood on safe airfields, antitank guns remained at storage depots, and whole armored divisions were spread out in a defensive position."

Deighton and Harman are equally unstinting in their praise for Admiral Ramsay and the Royal Navy, thopugh Harman punctures the myth that English civilians in private "little boats" had much effect. Harman seems to reach unnecessarily for the "news" that Dunkirk was not a victory but a defeat and a mythical boost to British morale. It was indeed both a terrible shellacking and a heroic recovery, or so it certainly seemed to this correspondent at the time and to the world at large. Both authors, incidentally, are charitably silent on what was transpiring in Fortress America, where warless folks were singing, ironically, Johnny Mercer's new tune "Fools Rush In," practicing the Lindy Hop and finding vicarious relief in the White Cliffs of Mr. Miniver.