Ronald Reagan's answer to Soviet invitations to negotiating a test ban treaty has been "testing, testing, testing."

But the blast in the Nevada desert was scrubbed two days running, and the president inadvertently participated, however fleetingly, in the moratorium that the Soviets have been observing unilaterally since July.

The explanation given by the Department of Energy for the Tuesday scrub was "high winds." Others gently ascribed to the White House more delicate motives. Tuesday marked the last official White House visit of Anatoliy Dobrynin, longtime Soviet ambassador, who has been called home.

Somehow, having the bomb go off while Dobrynin was talking to the president about a second summit seemed too gross. "CBS Evening News" pronounced it a "diplomatic wind."

Whether it was diplomacy or God was left to the imagination.

But there were other players. Enter the human element in the form of Greenpeace protesters. Greenpeace is claiming credit for the Tuesday scrub.

Greenpeace, an environmentalist organization associated with saving the whales, also tries to save the planet from nuclear tests. Until now its ability to confound governments was most vividly proved in July, when the presence of the Rainbow Warrior near a South Pacific test site so enraged the French that they blew up the ship -- and killed a crewman.

Greenpeace, well-financed and ultra-professional, conducts its "actions" with sophistication and theater.

Steve Loper, 31, of Chicago, a Greenpeace member who eluded the posse that rounded up five of his fellow protesters, said yesterday that his unknown whereabouts three miles from Ground Zero kept the authorities from pressing the button. He was not brought down from a tree until an hour and 45 minutes after the bomb was supposed to go off.

Yesterday the appointed hour came and went again with the "moratorium" still in place. This time it was scrubbed for a mix of "technical" problems, weather -- and the protesters, three of whom were on the site.

David Miller, a DOE spokesman, injected the currently chic terrorist issue into his explanation. "Some of them may be terrorists who have infiltrated the peace groups and have hostile intentions."

A Greenpeace spokesman said their members are carefully chosen and that Loper, a diver, is "well known to us."

"We have a long, proud history of nonviolent resistance," said the spokesman. "We have been the victims of terrorists, never terrorists ourselves. We protest on both sides. We sailed our ship into Leningrad Harbor to call attention to their tests and got towed out to sea."

The episode, of course, is maddening to the Reagan administration, which wants to continue testing, but quietly. The Soviet clamor for a ban is considered dirty pool because, as the White House huffs, "They know that Reagan will not accept it."

Various reasons are given: The reliability of the stockpile must be tested, although experts say that only 5 percent of the tests are for older weapons. Other reasons are that a test ban is small change for an administration that seeks the elimination of all nuclear weapons and that a halt would freeze unacceptably high stockpiles. Besides, they say, as they press forward with eight more tests this year, the Soviets are just dying to start theirs again and are digging holes in preparation.

The "verification" argument has faded somewhat since Mikhail Gorbachev offered on-site inspection. Recently, a rather desperate DOE official, George Miller, told The Wall Street Journal that testing is necessary for the morale of young weapons designers, who would quit if there were a moratorium.

The two foiled tests are headline news in Europe, the audience Gorbachev had in mind when he launched his appeal.

His obvious desire for an agreement feeds Reagan's determination to squeeze concessions from the Soviets. His resistance to all arms pacts is especially stiff now because he wants to wring more money from Congress for military spending and "Star Wars," the real reason for testing.

When Secretary of State George P. Shultz reported on the Dobrynin-Reagan meeting, he kept citing arms control as an "also-ran" on the second summit agenda.

The Soviets have now been given every reason to end their eight-month halt. But the curious moratorium proves that in stopping tests, the thing is to be there -- a discovery that could inspire the peace groups and put an end to "quiet" testing.