THE UNITED STATES temporarily withdrew

from the United Nations Conference on the Law of the Sea last March so that the new administration could review the terms of this complex international treaty that had been under negotiation for nearly a decade. The review has now been completed. Within the next few weeks the president will be deciding whether the United States will return to the negotiations and, if so, on what terms.

Among its many other provisions, the treaty establishes an international framework to govern mining of the rich mineral deposits found in the deep sea bed. The treaty holds that these minerals belong to no single nation, and therefore to all nations. But since only a few countries possess the wealth and technological capacity to mine in the deep sea bed, the treaty creates an international authority to mine these strategic minerals, along with private business, for the benefit of the developing nations.

It was dissatisfaction with the mining provisions that prompted the administration's almost year- long review. Some objections were to technical features, such as the allowed mineral production ceiling, that affect private interests' ability to secure an adequate return on their investment and their opportunity to compete on an equal footing against the proposed international enterprise. The source of other opposition was a distaste for the treaty's intervention in the traditional operations of the marketplace, and its spreading of political power in the treaty's governing council.

Some of the American concerns with the deep sea bed mining provisions can be corrected through relatively minor amendments. Others can be dealt with through the commissions that will put the treaty into effect after it is signed. The remaining difficulties for this country's mining interests will be small compared with the difficulties of undertaking such a risky and expensive enterprise on the high seas without--or worse, outside of--an agreed international framework.

More important, the sea bed mining provisions, despite the prominence they have acquired through the years of contentious negotiation, are only a small part of this treaty. American national security objectives are vitally affected by its provisions governing rights to military passage under and over disputed ocean territory and through vital narrow straits. Broader economic interests involve rights to fishing and to the development of oil and gas resources. The Law of the Sea also defines the freedom of commercial navigation and rights and responsibilities for scientific research and for environmental protection.

After nine years of work, the other participants in the Law of the Sea conference are determined to complete the treaty next year with or without the United States. Mr. Reagan's choice, therefore, is probably between abandoning the treaty altogether and proposing a limited set of amendments that could be adopted in the single short remaining negotiating session. Amendments that would undo compromises on major issues, reached over years of negotiation, have no chance that we can see of acceptance.

If this is true, the choice is pretty clear: the disadvantages to this country of trying to "go it alone" outside an international framework accepted by most of the rest of the world, in our view, outweigh the treaty's shortcomings. The damage to American national interests if the Law of the Sea were to collapse because of U.S. non-participation could be very great. And an American withdrawal at the last minute would not only provoke immediate anger and likely retaliation (restricted access to onshore minerals, impeded rights of military passage). It would also undermine a U.S. leadership position in numerous other international forums.