After that 'victory' on Law of the Sea

The bulk of US editorial comment following adoption of a Law of the Sea Treaty by the United Nations Conference on the Law of the Sea (UNCLOS) gleefully extols the victories of free enterprise over third-world socialism and ideology over pragmatism. It neglects taking the next step to inform us of exactly what the spoils are.

And no wonder. In the wake of the Law of the Sea ''victory,'' those companies which would mine the seabed of its deep-sea mineral wealth are pondering how they will now do so, given:

1. The virtual certainty that the UNCLOS treaty adopted on April 30 will be duly ratified by 60 nations and enter into force as international law;

2. The travesty of US diplomacy at the just-concluded conference session which brought home fewer improvements in the treaty text than the most inveterate pessimist could have imagined;

3. The likelihood that the Japanese and some of the European mining states will become party to the treaty, secure their mining rights under it, and reject any efforts to develop a competing ''mini-treaty'' regime;

4. The further likelihood that the legality of any such mini-treaty regime would be challenged in international court and lose; and

5. The unlikeliness of the Reagan administration's signing and ratifying the treaty in the near term, which could ultimately force the US mining industry to choose between abandoning deep-sea development plans or moving their operations abroad.

The future of the broader scope of national ocean interests is no less murky. While secure US access to strategic minerals in the international seabed is an important national goal, it is only one among many.

Sources of supply for strategic minerals appear and disappear with changes in market demand and the development of substitutes. There is no substitute for guaranteed rights of airplane overflight and ship navigation - whether to protect national security and international peace or to allow for the movement of vital oil supplies and trade in raw materials and manufactured products.

Nor is there any alternative to an agreed bottom line on protection of the marine environment worldwide: pollution in the Atlantic, Pacific, and Caribbean will eventually find its way to US shores no matter how stringent our national laws. To say nothing of conservation of the oceans' living species and protection of marine mammals - where one renegade nation can undermine the most well-considered and widely shared of such efforts.

Moreover, the majority of the nation's ocean scientists recognize that their freedoms to conduct oceanic research of value to all the world's peoples would be more severely curtailed absent a treaty. And treaty agreement to pursue the peaceful settlement of all ocean disputes goes further than similar provisions in any other international accord.

A great tragedy of the vindictive US decision to insist on a vote and vote against treaty adoption is that it will do much to foster mistrust of the US in that third-world arena identified by the Reagan administration as a critical battleground with the Soviet Union for hearts and minds. The ideologues who defeated the Law of the Sea pragmatists by impeding every effort to achieve reasonable and limited changes in the deep-sea mining texts justify their unbending stand on principle as a means to rebuild the American image abroad. Their actions speak more of the town bully than of the qualities of noblesse oblige which could restore confidence in American leadership.

The present ambiguity of the US government position might lead one to hope that the Reagan administration will now explore every avenue to achieve a small number of limited modifications in the seabed mining system. It should at least not hamper its industrialized allies from doing so. The administration should also refrain from taking any actions or making any statements which could irreversibly prejudge ultimate treaty signature and ratification by the US.

Because the nuances of the treaty just adopted guarantee existing US deep-sea mining companies continued rights and investment protections once the treaty enters into force, there is no need to foreclose US options at this time. The administration should therefore take part in and influence decisions in the Preparatory Commission set up by the treaty, whose role it will be to flesh out the regulatory system for mining prior to treaty entry into force. It should seize this remaining opportunity to continue the international dialogue, regain American prestige in the eyes of its allies and in the eyes of the world, and secure a regime of ocean law which on balance accommodates the full range of US national interests.