How do developing countries feel about nuclear proliferation?

While most try to pretend publicly that it is the least of their concerns, many of them privately spend a good deal of time worrying.

The Argentine-Brazilian rivalry is a case in point.

For the record, Adm. Raul Castro Madero, head of Argentina's Atomic Energy Program, insists he does not give a moment's thought to the possibility of Brazil acquiring weapon capability.

"We don't have any trouble with Brazil," Castro Madero said. "We cooperate as much as we can, and we do not distrust each other. I do not think Brazil will go for nuclear weapons."

Privately, however, Western diplomats say Argentine officials tell a totally different story.

Argentina, they say, defends its decision to construct an experimental reprocessing plant -- which will be able to produce plutonium for use in fabricating atomic weapons -- on the ground that Brazil plans to do the same.

"The Argentines are clearly worried about the Brazilians," a U.S. official says. "In private, they tell us they can't afford to let Brazil get ahead in nuclear technology."

The Indian-Pakistani rivalry is another case where actions speak louder than words.

Since India's 1974 underground atomic test, Pakistan has been making an all-out effort to acquire a nuclearweapon capability of its own.

India despite its "peaceful" explosion, insists it does not have a weapons program, and has not been building an arsenal of atomic bombs.

"We do not believe in nuclear deterrence," declares Foreign Secretary M. A. Vellodi.

India also does not suffer quietly any lectures on the dangers of nuclear proliferation.

"India was the country that introduced the term nonproliferation at the United Nations," says Vellodi. He suggests, moreover, that the more serious proliferation threat lies not in additional countries acquiring atomic weapons, but in the superpowers continuing to add to their nuclear arsenals.

"Our point is what has been done in this area of vertical proliferation?" he asks.

Vellodi says one of India's primary concerns is for the superpowers to rapidly conclude work on a complete nuclear test-ban treaty.

"We've been told for some time that a complete test ban is around the corner," says Vellodi. "The world community is becoming worried about this delay."

Sigvard Eklund, director-general of the International Atomic Energy Agency, endorses the need for a complete test ban treaty if there is to be any hope of preventing the spread of nuclear weapons.

"I think a total test-ban treaty is a moral necessity," Eklund says. "To tell more than 100 non-nuclear weapon states that they should not require nuclear weapons, and every week be reminding them with a nuclear test -- these two things do not go together."

Eklund also suggests that if a complete test-ban treaty is not concluded by 1980, some nations may decide to withdraw from the Nuclear Nonproliferation Treaty.

"I think we will learn in 1980 how upset they are," Eklund says, and if nations do begin to withdraw from the nonproliferation treaty, he adds, "It would create a very unpleasant situation."