Setting date and plot line for Summit II (and an eventual III)

Moscow and Washington went through one more round of fencing this week over the when and the what of a second Reagan-Gorbachev summit. Setting the date and plot line for R-G Summit II (and an eventual III) is not unlike producing a working script, filming schedule, and release date for movie sequels II and III after a box office hit.

We are now at the stage where technical advisers critique details in the tentative script.

Much of what both superpowers state publicly and leak semi-publicly is intended to hold the allegiance of spectators while the technicians and leaders puzzle out each other's moves on present and future missile capability.

There is bound to be lingering uncertainty about summit timing and content when: (1) Two large bureaucracies jockey toward agreement. (2) Hawks and doves in each camp alternately win the ear of their leaders. (3) Kremlin and White House calendars are full of obstacles to be worked around.

But some facts seem relatively clear.

It is likely, for instance, that the next two months will be filled with intensive analysis of the two sides' latest positions on offensive intercontinental missile reduction and future defensive arms restrictions.

Moscow's recent offer calls for about a one-quarter cut in intercontinental missiles and reduced multi-warhead capability. It asks in return for United States adherence, through the year 2000, to limits on defense missiles that can shoot down incoming missiles -- limits agreed to in the 1972 Anti-Ballistic Missile Treaty. It then asks for agreement on how much ``star wars'' defense research and development will be permitted.

An American counteroffer is being shaped.

Added to that will be discussions of more reliable verification methods to assure that any deal agreed on will not be undermined by accusations of cheating.

Longtime Soviet footdragging on verification may be easing. General Secretary Mikhail Gorbachev vaguely hinted as much earlier this year. The Chernobyl nuclear disaster added to pressures for relaxing secrecy. Moscow this week admitted an unofficial team of US scientists who plan to set up a year-long monitoring experiment for underground nuclear tests. And the letter that new Soviet Ambassador Yuri Dubinin delivered from Mr. Gorbachev to President Reagan last week contained a proposal for US and Soviet specialists to meet soon to discuss means of making verification more reliable.

Next, in mid-September, foreign ministers George Shultz and Eduard Shevardnadze should meet to set a date for their bosses to meet. Gorbachev and his shrewd new ambassador to Washington are making it appear that a September SH-SH (Shultz-Shevardnadze) meeting is iffy, depending on the technicians' progress. But, in fact, the superpower foreign ministers meet almost routinely at the UN each September to discuss their relations and world trouble spots.

It seems probable, though not certain, that by the time of that meeting the two ministers will be able to pick out enough areas of concrete arms progress to schedule Summit II. Their ability to do so may depend on whether either Reagan or Gorbachev is in enough of a hurry to be willing to accept less than a full loaf for ratification at a summit.

Diplomats from third nations suspect that both great communicators are more interested in speed than either one lets on. Reagan theoretically needs prompt action more than his competitor, because by fall he will have only two more years in power. If he wishes to gain historical credit not only for a big military buildup but also for use of that strength to bargain down weapons and weapons costs, he will need to see progress by next year.

Some specialists see Reagan's announcement about abandoning compliance with the limits of the second Strategic Arms Limitation Treaty (SALT II) as a goad to force the pace of bargaining. If so, it's aimed at long-range and short-range offensive missiles, and the future scope of defensive-weapons development.

But Gorbachev also may want speed. He has been trying to sustain an appearance of momentum. He began by clearing out managerial dead wood even while his predecessor, Konstantin Chernenko, clung to office. He continued with wholesale new appointments to party and management posts, and imposition of modest factory-profit reforms. Then came Summit I, followed quickly by Gorbachev's showcase party congress.

The new leader was so busy that he appeared to be unable to produce more than a rhetorical generalization about a new arms position. His negotiators in Geneva had to tread water for eight months while they waited for detail from Moscow. Overhaul of the Kremlin foreign-policy apparatus awaited the arrival of Anatoly Dobrynin as a kind of national security council chief, following his long stint as Moscow's man in Washington.

This spring, Gorbachev's first anniversary, saw some steady but modest gains in industrial production. But the Soviet boss may need and want further evidence that he can keep up the pace of change. And any arms cutback that results in either (1) lowered arms budgets or (2) at least relief from super-expenditures on another big arms race would allow him to pursue more change in the economy. Such super-expenditures could result from both a defensive Stragetic Defense Initiative race and an offensive weapons race if SALT II is not replaced with a Strategic Arms Reduction Talks (START) agreement.

Meanwhile, Mr. Shultz and Mr. Shevardnadze will not lack for other serious subjects if they meet in New York this September. This week both southern Africa and Nicaragua pushed back onto their most active lists.

South Africa, in particular, is causing a lot of reassessment. Britain's ties to its Commonwealth associates have gradually squeezed Prime Minister Margaret Thatcher into promising some kind of sanctions after just ``one more'' talk in Pretoria. Such sanctions would be all but meaningless without a united front of South Africa's main trade partners. So West Europe's leaders have also been trying to agree on a trade threat that would put Britain and West Germany in step.

Washington is also reexamining its policy of quiet jawboning. The White House is pressed by domestic political considerations in a tight election year, as well as by international pressures.

Pieter Botha's government in South Africa has reacted once more by threatening countersanctions. These would restrict trade and labor movement, damaging the economies of neighboring black African states.

In the midst of this maneuvering, the South African government ended, on schedule, the ``pass laws'' for blacks. That was one of the ``reform'' steps by which the regime seems to be trying to combine policies of divide-and-conquer with limited black-white power sharing.

The problem for this strategy is that such reforms are overtaken and canceled out by the imposition of harsh new arrest, detention, banning, and censorship regulations. The strategy of getting to power-sharing with ``moderate'' groups seems to be driving more moderate blacks into supporting militant groups. Thus, instead of undermining the militants, government actions appear to be stiffening support for them.

Joseph C. Harsch is on vacation