Hobart Rowen is to be commended for his advocacy of substantial U.S. aid to the Soviet Union {"Staving Off Soviet Chaos,'' op-ed, Nov. 29}. However, he understates the case. ''The real issue,'' Mr. Rowen says, ''is not the amount of aid or credits that the United States can afford ... but the political symbolism involved.'' It seems to me that the real issue is the political realities involved. Both the United States, the Soviet Union and, in the long run, the entire world could benefit from a massive, sustained U.S. assistance program on the scale of the postwar Marshall Plan.

Opponents of aid to the Soviets argue variously that (1) we can't afford it, (2) it won't reach them and (3) they don't deserve it anyway.

On the first point, it can be assumed that a nation that can spend $1 billion a month to keep nearly half a million men and women sitting in the Arabian desert can afford quite a lot, even at the cost of considerable personal sacrifice. And unlike the president's dead-end Gulf adventure, money spent on Soviet aid would have constructive effects: feeding, clothing and fostering the amity of a people whose friendship with us is vital to any future worldwide endeavors. A government-directed aid initiative could provide a needed boost for U.S. industry and agriculture at little greater cost than subsidies.

The problem of aid distribution within the Soviet Union is real but not insurmountable. It is more than anything else a widespread lack of confidence and fearfulness that have led to the systemic breakdown. Generous Western -- and especially American -- food relief and other support would by itself do much to instill confidence and allay fears. And in any case, the paleolithic Soviet distribution system must be overhauled before the U.S.S.R. is ever to become a viable market for Western goods -- we might as well help them to do this now.

The argument that the Soviets, or at least their government, do not deserve Western assistance is morally disagreeable and politically foolish. In the same issue as Mr. Rowen's column, a letter writer cites the Soviet blockade of Lithuania as a reason not to send aid to Moscow. But by adopting the opposite stance and contributing generously and without political conditions, we shall very likely both alleviate much hardship and also further our own national interest. DAVID SCHAUFFLER Bethesda

Hobart Rowen writes that among the serious consequences harmful to Western interests is "a breakup of the Soviet Union into its multiple parts."

Why is that bad?

For some 70 years, the Soviet Union has been an artificial state fused from many nations under duress. Because it is artificial, it cannot survive the natural desires of its peoples for self-determination. Compelling antagonistic nations to stay together against their will is the worst recipe for chaos and propels greater strife than any economic crisis ever could.

Better to help the U.S.S.R. quietly dissolve into its organic national parts. Once boundaries of all nations and rights of all those therein are securely guaranteed, the peoples of the nations now trapped within the Soviet Union can get along with the business of building their own prosperity and security. Strong fences make better neighbors.

MARTIN B. TATUCH Arlington

The editorial "Food Aid for the Soviets" {Nov. 19} raised a number of doubts about the rationality of giving aid to the U.S.S.R. but missed the need for a linkage between the possible aid and the problems of security.

Nuclear anarchy is likely in the Soviet Union because political anarchy is inevitable there (unless, of course, there is a strong conservative crackdown). Therefore it is strange for the American government just to continue the policy of gradual bilateral cuts of the nuclear arsenals as if the Soviet side were a normal and stable partner in negotiations.

Mikhail Gorbachev really deserves the Nobel Peace Prize if he understands that it is irresponsible and immoral to continue to spend one-quarter of the Soviet gross domestic product for defense purposes against the background of possible famine in the U.S.S.R. President Gorbachev should be helped if he reduces unilaterally the Soviet nuclear arsenals to the minimal level and frees the world from the threat that comes from the collapse of the Communist system.

The U.S. government and public opinion can do a lot to help this happen. Generous economic help should be offered to the Soviet Union even if Western economies themselves are having difficulties. But this help must be strictly linked to the unilateral cuts in the number of Soviet weapons that endanger the world. ANDRUS PARK Washington

The writer, a member of the Estonian Academy of Sciences, is a visiting fellow at the Wilson Center.