Sen. Daniel P. Moynihan has written to me to say, in effect: See -- see what you and your dumb friends have gone and done? He refers to the World Court's decision, against the United States and in favor of Nicaragua, asserting that said court does have jurisdiction over the quarrel between the contending parties. That quarrel arose over our mining of Nicaragua's harbors last spring.

Now there are several strands in the controversy. The first has to do with when exactly the United States asserted that the World Court would have no jurisdiction. Our government made that assertion after it had been discovered that we were engaged in mining Nicaragua's harbors. As someone remarked at the time, you don't plausibly deny to the court jurisdiction the moment you hear that a petitioner has filed suit against you.

The analogy, however, is not entirely useful precisely because the United States was engaged in secretly mining the harbors. One cannot go to the World Court and announce, in advance, that when Nicaragua discovers the mining and files suit against us, we will not accept the court's jurisdiction.

The answer to all this is that the United States shouldn't have maintained secrecy in its operations. It was the Carter administration that publicly charged Nicaragua with proceeding with what its officials have frequently called their "revolution without frontiers" by attempting to arm guerrillas in El Salvador. Committees in the House and Senate surveyed the evidence and agreed with the finding of President Carter. So the first mistake was to have proceeded secretly when to do so served no clear purpose.

The second mistake was to have agreed to argue before the World Court that said court did not have jurisdiction. Why? For several reasons. One is that the World Court's deliberations are by no means to be trusted. It is heavily influenced by Third World pressures, in turn heavily influenced by Soviet and Soviet- satellite pressures. But the primary reason for not arguing the government's case is that our decision to argue casts a shadow of illegitimacy on our own case. A sovereign power should not submit sovereign decisions to other bodies to rule on.

The government's legal case was based on the senior applicability of Article 24 of the United Nations Charter, which asserts that the United Nations confers on the Security Council "primary responsibility for the maintenance of international peace and security." Article 33, on which Nicaragua relied, refers to the World Court in a paragraph that enjoins parties to any dispute to seek solutions "by negotiation, arbitration, judicial settlement, resort to regional agencies or arrangements, or other peaceful means." In the 39 years of its life, the court has heard all of 40 cases. Mostly, in substantive cases, it has been ignored. Fewer than a third of the more than 150 members of the United Nations recognize any authority of the World Court.

Professor Abram Chayes of Harvard, who went over and pleaded the case on behalf of Nicaragua, was also (like Moynihan) an outspoken critic of the U.S. liberation of Grenada a year ago -- on the grounds of its illegality. What is legal in the world of Chayes and Moynihan? That question is posed inquisitively. Is the government of Nicaragua legal? It would be difficult to find a responsible diplomat who would seriously argue that the government of Nicaragua is the legitimate instrument of the Nicaraguan people.

Moynihan is correct in saying that we have done ourselves damage. But that damage was not in laying down those mines, though that decision is tactically challengeable. Our damage was self-inflicted. If the World Court were to be trusted with the security of the United States, then what are we doing clinging to a veto in the United Nations -- a veto that Moynihan so grandly used when he was our ambassador there?