IMAGINE THAT the Red Army rolls into West Germany and that it appears that conventional NATO forces can contain it.

Imagine, however, that this effort is undercut because the four-star generals commanding the U.S. Air Force and Army units under the U.S. European theater commander are slow in obeying his orders because they are conferring with their service chiefs in Washington.

Then imagine that the Army commander, against the wishes of the theater commander, stored most of his ammunition in depots that turn out to be in tactically bad locations.

This is not a pipe dream. Except for the movement of the Red Army, the other elements have already happened, according to Sens. Barry Goldwater (R-Ariz.) and Sam Nunn (D-Ga.), the chairman and ranking minority member of the Senate Armed Services Committee, respectively.

They have painted a dismaying picture of conventional U.S. military capability in their recent speeches before the Senate and which will be featured in a Senate Armed Services Committee staff report scheduled to be released this week.

The fault goes far, far beyond the old business of mean sergeants, lousy chow and nitpicking officer martinets. Listen to Goldwater's opening words:

"You will be shocked at the serious deficiencies in the organization and procedures of the Department of Defense and the Congress. If we have to fight tomorrow, these problems will cause Americans to die unnecessarily. Even more, they may cause us to lose the fight."

They're not talking about the quality of the officers and men in uniform, who are probably the best in the world, or their weapons and equipment, which are a lot better than many think after reading news stories about all the failures. They're talking about organization, those chain-of-command lines and boxes that tell who does what and how orders, decisions and other information are transmitted.

And Goldwater and Nunn are not talking abstractions. They are talking of failures in command unity and coordination that have already showed up in U.S. casualty counts.

The villains are politics and bureaucracy.

Rivalry between the individual services has been too great to allow truly unified commands. The Joint Chiefs of Staff are joint in name only -- they function more as spokesmen for their services.

Right now, the United States has a number of supposedly unified theater commands -- the four-star commanders-in-chief of the Atlantic and Pacific (CINCLANT and CINCPAC) and in Europe, for example. But they have four-star Army, Air Force and Navy officers under them, each commanding their service components. As often as not, these component commanders take their orders from their service bosses in Washington, not the theater commanders who are responsible for the actual fighting.

Another villain that Goldwater and Nunn identify is Congress, which has been derelict in its oversight. The debate on the Hill has focussed on the Pentagon budget and has tended to ignore what national- security strategy should be and how we should carry it out.

Therefore, there is little emphasis on coordination between the services in achieving that strategy. Most energy goes into the wasteful and duplicative hassles over the defense budget each year. As Goldwater points out, this is done three times a year in both House and Senate by the budget committees, the armed services committees and the appropriations committees.

These deficiencies are as old as the republic and in Goldwater's words have already "led this nation to military disaster or near-disaster," not once or twice but repeatedly.

During the Spanish-American War, he recounts, the Army and Navy commanders in Cuba couldn't agree on a plan to seize Santiago so the Army had to take the city without naval support.

In World War I, coordination of naval gunfire and tactical air support were not major problems for the American Expeditionary Force. But at Pearl Harbor, on Dec. 7, 1941, these failures of command communication and coordination had tragic consequences. Adm. Husband E. Kimmel and Gen. Walter Short weren't feuding, they just each talked to Washington without consulting with the other. As a result, the Army assumed that the Navy was conducting long-range aerial reconnaissance while the Navy assumed that the Army's radar was fully functional. Neither was correct.

This lack of interservice coordination continued throughout World War II when Gen. Douglas MacArthur had command of the Southwest Pacific and Adm. Chester Nimitz had the rest of the Pacific.

It also was a factor in the Vietnam war.

"Each service, instead of integrating efforts with the others, considered Vietnam its own war and sought to carve out a large mission for itself," wrote Gen. David Jones, a former chairman of the Joint Chiefs of Staff. "For example, each fought its own air war, agreeing only to limited measures for a coordinated effort . . . . Lack of integration persisted right through the 1975 evacuation of Saigon -- when responsibility was split between two separate commands, one on land and one at sea; each of these set a different 'H-Hour,' which caused confusion and delays."

Have we learned anything since? Not so you could notice it. The Iranian hostage- rescue mission came to disaster partly because of interservice rivalries that led to disagreements on mission concept, faulty planning, training and incompatibility of equipment, such as radios.

One major contributor to the tragic deaths of the more than 241 Marines in Lebanon two years ago was a chain of command that had at least eight layers between the president and the troop commander on the ground, including the secretary of defense, the U.S. commander in Europe and the Sixth Fleet commander in the Mediterranean. The result was that the nature of the Marines' mission -- whether diplomatic or military -- was fuzzed, guidelines for security were fuzzed and responsibility for the lack of security was fuzzed.

Finally, Nunn tells a story about the invasion of Grenada that gives meaning to the fact that the armed forces didn't want journalists there because they would report every little error.

Officers of the 82d Airborne couldn't call for naval gunfire support because their radios were incompatible with the Navy's. One officer borrowed a Marine radio but that didn't work because he didn't know the Navy codes and procedures. In desperation, one paratroop officer used his AT&T credit card to call Fort Bragg, N.C., to try to get the Army to communicate with the ships off Grenada.

For all the focus on both weapons procurement and the upcoming arms control talks in Geneva, these mundane matters are of life-and- death importance. Goldwater and Nunn are performing a signal service. Will anyone listen