Washington — No one has ever seen anything quite like the debate that is sweeping the country over nuclear weapons and what to do about them.
The latest development is the joint declaration by four former senior government officials that the United States and its allies should formally pledge not to make first use of nuclear weapons in Europe. This is accompanied by the counterdeclaration by Secretary of State Alexander M. Haig Jr. that the proposed ''no first use'' pledge would end Western credibility with Moscow.
This is only one of the signs of mounting national and worldwide concern over nuclear weapons, a situation created, in Mr. Haig's omimous words, because ''man has conceived a means capable of his own destruction.''
The sudden argument over ''no first use'' falls into step with the continuing dispute over whether to support an international agreement to ''freeze'' nuclear weapons production at its present level.
Spurring on the debate is the sudden sharp emergence in the United States of a heightened public awareness of the perils of nuclear proliferation.
This month publishers issue at least eight books on nuclear dangers. They are led by Jonathan Schell's ''The Fate of the Earth.'' A paperback, ''Nuclear War: What's In It for You?,'' is coauthored by Roger Molander, executive director of the Washington-based Ground Zero, which describes itself as a nonpartisan educational group studying nuclear issues. The groups plans to hold nationwide conferences April 18-25.
Magazine cover stories--''Thinking about the Unthinkable'' (Time, March 29) and ''A New Outcry Over Nukes'' (Newsweek, March 29)--trumpet the national agitation.
Mr. Schell's book, one of the most widely talked about of the year, describes the dimensions of nuclear conflict in arguing for a reordering of mankind's way of settling disputes. He says that a medium-sized weapon in a present-day nuclear arsenal has the explosive force of 1 million tons of TNT, that the Hiroshima bomb had only 12,500 tons, that some 50,000 warheads are in existence, that they have an explosive yield of 20 billion tons of TNT, and that more are being added every day.
The pressure is building on all sides for some kind of solution to what many people--common men and women and well as those in positions of power--see as the crucial issue of our times. Politicians are being forced to take notice.
Some 257 New England town meetings passed antinuclear weapons resolutions. California Gov. Edmund G. Brown Jr. has endorsed a California initiative to put a nuclear freeze proposal on the November ballot. Grass-roots antinuclear movements proliferate in Colorado, Chicago, South Dakota, Minnesota, and elsewhere. The National Council of Churches and some 70 Roman Catholic bishops have spoken out. Politically, it looks like a movement poised for somebody to grab.
President Reagan, whose administration is seeking some way of coming to terms with the nuclear issue, argues that he is going as fast as is safe in disarmament negotiations with the Soviets. But pressure for quicker action dominates the new nuclear-freeze movement.
Washington journalism has rarely seen such a gathering of international reporters as jammed the press conference April 7 to hear four former government officials, led by Robert S. McNamara, defense secretary from 1961 to 1968 and World Bank president, 1968-1981. They proposed that the US pledge itself against the first use of nuclear weapons in a European conflict. The four, seated in a line, also included McGeorge Bundy, national security adviser, 1961-66; George F. Kennan, former ambassador to Moscow; and Gerard Smith, leader of the Nixon disarmament delegation that negotiated SALT II. The Soviet Union has urged such a pledge and promised to obey it.
Secretary Haig preceded the no-first-use presentation with his own counterargument. He said at one point:
''If the West were to allow Moscow the freedom to choose the level of conflict which most suited it and to leave entirely to Soviet discretion the nature and timing of any escalation, we would be forced to maintain conventional forces at least at the level of those of the Soviet Union and its Warsaw Pact allies.''
It would mean the return of the military draft in the United States, he declared.
As the argument gathers strength, it carries passionate undertones. The joint article in Foreign Affairs argues that the risk of Soviet aggression ''has never been as great as the prophets of doom have claimed,'' and adds at one point, ''As long as the weapons themselves exist, the possibility of their use will remain.''