ALEXANDER HAIG, President Reagan's erstwhile Secretary of State, probably won't be remembered for his command of the English language. In fact, short of outright translation, careful scrutiny of his every utterance was required to decipher precisely what the Secretary was trying to say. But one infamous remark of Haig's came across loud and clear. Seeking to reassure the American public in the aftermath of the assassination attempt on Reagan two years ago, Haig stated at a nationally televised press conference. "I'm in control here."

That the Secretary's words elicited vivid protests from the press, government officials and the general public was not surprising. After all, Haig had conveniently boggled the line of succession to place himself ahead of the Vice President and the Speaker of the House. And Americans are sticklers for procedure. As citizens of constitutional democracy, we are convinced that the game of government must be played in strict adherence to the rules, particularly in times of crisis. At any given moment, we expect to find that the person who should be in charge really is running the show. That person, in turn, is deemed accountable for any initiatives taken and eventually suffers the consequences if those initiatives are condemned by the public. William Calley, the man who ordered his troops to slaughter the inhabitants of My Lai, can attest to that. So can Richard Nixon.

In the Soviet Union, ask the question "Who's in charge?" and the response will likely be a blank look. Back in Washington, Kremlinologists spend the better part of each working day trying to figure out which member of the Central Committee has the upper hand. Officially, of course, Yuri Andropov gives the orders. But because Soviet policy is made behind perpetually closed doors, no one can really be sure.

The downing of KAL Flight 007 provides what may be some very disturbing answers to the query at hand. For as more and more details concerning the incident emerge, it seems increasingly clear that the decision to shoot down the plane was made solely by the military. These details include:

*U.S. intelligence reports that Andropov and his top advisers were not in Moscow while the drama was being played out and were not in contact with military officials.

*A statement made by the head of the Soviet armed forces to an extraordinary gathering of Russian and foreign reporters claiming the orders to shoot down KAL 007 were given by a regional commander who did not consult government officials.

*Criticism of the Soviet fighter pilot's actions by Viktor Linnyk, a political consultant in the Soviet Department of International Affairs, who accused the pilots of being "trigger-happy."

*A statement to reporters by Viktor Afanasyev, editor-in-chief of the Communist Party daily Pravda, chastising Soviet military leaders for waiting six days before admitting the airliner was shut down.

ALL OF THESE FACTS and comments inducts clearly that the military acted on its own initiative. Which is not to conclude that "the generals are in charge," but simply to note that the influence of the military in the Soviet Union has increased to the point that generals can make crucial policy decisions without consulting their civilian cohorts.

The more common this phenomenon becomes, the greater the danger for confrontation between the superpowers. Civilian leaders, even in an authoritarian regime, tend also to be politicians, though on an international as opposed to national stage. Yuri Andropov, had he wanted to shoot KAL 007 down, would nevertheless not have done so had he been in charge. His geo-political concerns--like the attempts to "neutralize" Western Europe, court the Third World and avert if possible the deployment of U.S. cruise and Pershing II missiles on the Continent--are too great and present in his mind to have permitted such an act. Military leaders, on the other hand, like to use the hardware they have been given. And they tend to think more in terms of power plays: a little show of force is, to them, the best tool of diplomacy.

Given this state of affairs, it seems logical to wonder why the power of the Soviet military within the decision-making process has increased. At least part of the answer to that query is clear enough: international tension. When a Cold War mentality comes to characterize the relationship between the superpowers as it does now, those on each side who advocate increased strength and even confrontation come to the fore. The Soviet generals, much like their American counterparts, have a good case to make to the civilian government and even, were it necessary, to the public. Detente isn't working, they are saying. The Americans refused SALT II, are putting new missiles in Europe, haven't proved flexible in Geneva and are becoming increasingly inflamed by outrageous rhetoric. Give us a chance to show you what we can accomplish.

THE ONLY SANE POLICY this country can adopt is one that promotes the power of the Soviet civilian government at the expense of the military. Increased defense spending, the MX missile system, rhetorical duels and the like will serve solely to give the generals a boost. Detente--which didn't work simply because it was never really tried--is the solution. Increased economic, scientific, cultural and educational exchange, all mutually beneficial propositions, certainly won't make the current Soviet-American relationship worse. And these policies might just help any moderates that exist within the Soviet power structure to assert themselves, and at the same time hold the generals at bay.