US may find itself high and dry unless it signs Law of the Sea treaty

The United States will eventually climb on board the Law of the Sea treaty, says a former head of the US LOS negotiating team.

''I think we're going to conclude it will really cost us to be out,'' said Elliot L. Richardson, Republican Cabinet veteran and LOS chief from 1977-80, at a July 21 breakfast with reporters.

President Reagan has announced he will not sign the pact because, he says, it doesn't adequately protect US seabed mining interests. But this objection is based on mistaken assumptions and bad advice, says Richardson. Specifically, he says the administration is not recognizing two facts:

1. Without a treaty, US firms won't mine the seabed floor. Such underwater operations require huge sums of capital - money corporations will be reluctant to commit unless they have international legal protection. Bilateral agreements between major economic powers won't provide that assurance, says Richardson.

2. The US won't be able to take advantage of treaty provisions it supports - such as navigational freedom for warships - without signing the pact. While administration officials say such sections will simply become embodied in international law, Richardson says legal challenges could block the US from enjoying these benefits.

''We can't pick and choose among the rights and responsibilities of the treaty,'' he says.

Richardson admits he is regarded as a ''stuck whistle'' on this issue, continuously calling for the US to sign the sea treaty.

Some White House advisers had real concerns about defects in the seabed mining provisions, and feared the treaty's effect as an antifree market precedent for other multilateral negotiations. But it was ''idealogues'' with a distaste for any kind of supranational institution who finally scuttled US participation, claims Richardson.

Ironically, Reagan's brusque tactics on Law of the Sea - such as the March 1981 firing of top-level US negotiators - were a ''shock treatment'' that could have pried further concessions out of the convention, says the former chief LOS negotiator.