Washington — Upstairs at the Sheraton Washington Hotel, Gen. Glenn K. Otis, commander in chief of the US Army in Europe, is talking about ''airland battle,'' the new Army doctrine for defeating a Warsaw Pact attack. This is an important new departure in military planning, and whether or not it works could determine the survival of the Atlantic alliance. But two-thirds of the seats in the dimly lit convention hall are empty.
Ah, but downstairs, friends, the caissons are really rolling!
It's wall-to-wall uniforms and three-piece suits, handshakes and backslaps, all sparkle and flash in a din of happy commerce. There are money and careers to be made, yessir, in this burbling mix of Las Vegas, Marrakech, and the Pentagon, this energetic display of the military-industrial complex at its most obvious.
The Association of the United States Army, a private group of retired military personnel and defense contractors, held its annual meeting here a few days ago. And while the secretary of the Army, the Army chief of staff, and other senior officials appeared, the 200 exhibits set up by armsmakers and peddlers from around the world were where the action was.
There were tanks in the parking lot, helicopters on the roof, and a maze of booths hawking everything from the most advanced anti-tank missiles to your basic, garden-variety ''combined effects munitions'' (cluster bombs).
There were slot machines. There were raffles for a gold-plated golf putter and a fresh lobster. There were card tricks. ''Doesn't this make you think of Pratt & Whitney?'' one quick-shuffling dealer enthused.
There was Miss Maine, in tiara and white sash, helping publicize the guns built by a home-state company. ''They have a nice little pistol over there,'' she said. ''Just two pounds, loaded.''
There were attractive young women, some in white jump suits, others in olive drab short shorts or khaki miniskirts. ''You want your picture taken with the gals?'' the man from Rockwell International asked passers-by, offering instant snapshots with his company's light armored vehicle in the background.
A booster of the ''Hellfire'' missile explained that there were several targets for his promotional campaign here: other contractors, US Defense Department officials, and foreign representatives - not including the two gentleman from the Soviet embassy, carefully scrutinizing a Patriot anti-aircraft missile.
''And we talk to congressional types,'' he explained. ''As you know, budgets are a yearly thing.''
Military advancement - especially when there is no war to display one's ''right stuff'' - often must include success in developing, procuring, and deploying new weapons systems. This has never been more true for the Army - traditionally behind the Navy and Air Force in big weapons buys - which is now acquiring more new high-tech equipment than ever.
At this convention were battalions of mid-ranking officers perusing displays from around the world. A young lieutenant colonel exchanged cards with an armaments salesman from Spain. ''I'm definitely interested,'' he said, as he walked off with four bags full of brochures and trinkets. ''I will contact you.''
''I'm like a kid in a candy store,'' said a major as he looked over the Ultimax 100 5.56-mm light machine gun built by Chartered Industries of Singapore. Nearby, a young civilian executive concentrated fiercely on Atari's ''Battlezone'' video game set up by one arms merchant.
Somehow, as one surveyed this essence of national security at its most commercial, the words of Herman Melville came to mind: ''All wars are boyish, and are fought by boys.''
It wasn't just the G. I. Joe atmosphere here, the fact that the high-priced ''long-range fast-attack vehicle'' looked very much like a dune buggy with machine guns fore and aft. Or the antiseptic cast to highly lethal weapons of war, the videotaped bazooka demonstrator noting casually that ''survivors can be expected to retreat from such an attack.'' Little talk of killing here.
It was also the comments from young soldiers - some with recent combat experience - as they surveyed what a retired general described cynically as ''the greatest military show on earth . . . breathtaking displays often devoid of any enemy action.''
There was the young sergeant (too young to have been in Vietnam) listening to the machine-gun peddler's pitch.
''What happens if you fall in the mud?'' the practical ground-pounder asked. ''No problem!'' was the enthusiastic salesman's reply. The sergeant seemed dubious.
There were also the two young members of Britain's Royal Marines, 42nd Commandos - Sgt. Andrew Jones and Lance Corporal Bill Bone - who talked about their fierce night battle against Argentine machine-gun nests to take Mount Harriet in the Falklands. They credited their success to relatively simple shouldered-fired rockets that had been thrown on the beach and soaked in salt water - ''not treated with any finesse,'' as Sergeant Jones put it. Even here, however, the marines reported fewer direct hits than the rocketmaker was trumpeting based on his test firings.
At a briefing for reporters, the British marines were introduced by retired US Army Gen. Mike Lynch, who had received a battlefield commission as a combat squad leader in World War II. He took a dim view of much of the high-tech weaponry on display, and urged Army planners to listen to the ''doughfeet.''
''With increasing frequency I'm seeing combat needs adulterated with theoretical hogwash,'' he said.
''Remember that all these wonders are designed to help the lowly infantryman succeed in battle,'' said this veteran of three wars.
''He knows what he needs. It's when the colonels and generals try to decide what they need that it becomes complex and expensive. . . . Fabricating a mythical battlefield and then designing and building weapons based on your own creation is dangerous.''
Next door, meanwhile, the arms bazaar continued.
Did she know much about the machine gun she was helping to sell? Miss Maine was asked.
''I know enough to know that if I shoot it wrong, I can get hurt,'' she said.
Here, however, the smoke and din of battle was merely budgetary. And the only target was Uncle Sam's wallet.