Baker to Offer New Arms Proposals : Diplomacy: The package will include a compromise on air-launched cruise missiles.

Secretary of State James A. Baker III will take “a good package” of arms proposals to Moscow this week, including ideas that go beyond the agreed agenda, in an effort to complete the START nuclear weapons treaty this year, U.S. officials said Saturday.

Baker, who leaves Monday for East Europe and the Soviet Union, will spend three days with Soviet Foreign Minister Eduard A. Shevardnadze discussing the START treaty, which would cut by half the number of offensive nuclear warheads in the superpower arsenals.

In talks beginning Wednesday, Baker will offer a compromise to settle the longstanding issue of how to count air-launched cruise missiles and will propose a limit on the number of warheads that can be carried on mobile, land-based ballistic missiles, sources said.

The Pentagon also wants Baker to propose counting some of the warheads on Soviet mobile missiles against the warhead limit on Soviet fixed, silo-based ICBMs--the weapons most threatening to the United States in a nuclear war, according to officials.

Whether President Bush and his top Cabinet officers agreed to the Pentagon proposal when they met Thursday was not known. But the consensus among officials and non-government experts familiar with the concept is that Moscow is unlikely to accept it because the restraints would affect only Soviet forces. The United States has no such mobile missiles at present.

Baker, moreover, has opposed general calls by conservative politicians and arms experts to make radical new demands on the Soviets in the belief that they are “on the run” and would now accept offers they previously rejected.

Instead, he has shunned proposals that might threaten to derail or delay significantly the START--Strategic Arms Reduction Talks--treaty. Both Bush and Soviet President Mikhail S. Gorbachev want to have the pact settled in principle at their next summit in June and fully completed by the end of 1990.

The correct approach, Baker has said, is to “lock in” the treaty, already almost 90% completed, “while we have the opportunity,” a reference to Gorbachev’s apparent willingness to finish the process.

In contrast with some previous negotiating sessions, the American team hopes to avoid disclosing many of its new ideas if they are unacceptable to the Soviets, in order not to create new obstacles or poison the atmosphere.

“The aim this time will be to get results, not to demonstrate any ‘bold new thinking’ to the public,” one official said Saturday.

While strategic nuclear arms will be the main topic of the trip, Baker also is expected during his four-day stay in Moscow to provide greater detail about Bush’s new proposal to slash U.S. and Soviet troop strength in Central and Eastern Europe.

In his State of the Union address, Bush proposed ceilings of 195,000 troops for each nation in Central and Eastern Europe, but he also said the United States would retain an additional 30,000 troops in Britain, Turkey and Italy.

The Kremlin, as expected, expressed opposition to the inequality built into the scheme even though, in principle, the Soviets could station 30,000 troops in southeastern European nations such as Romania and Bulgaria in addition to the 195,000 in Eastern Europe.

That possibility, however, is considered unrealistic because those nations have never had Soviet forces and because of the ousting of pro-Soviet governments in the region’s current upheaval.

Moreover, according to one source, the Bush proposal would not bind the United States to a ceiling of 30,000 outside the so-called central zone in Europe. That figure is considered a “force projection,” meaning an expectednumber that could be increased at will.

Baker, who will meet with Gorbachev and appear before a foreign affairs committee of the Supreme Soviet legislative body later in the week, also is expected to discuss with Soviet leaders the implications of the continuing upheavals in former Soviet Bloc nations.

German reunification, to which Gorbachev now appears to be less opposed than last month, will be a prime topic as both superpowers seek to keep the process of bringing East and West Germany together both gradual and peaceful.

In addition to his sessions with Soviet officials, Baker will confer briefly with French Foreign Minister Roland Dumas during a refueling stop in Ireland, spend a day in Prague meeting with President Vaclav Havel and other leaders of the new government in Czechoslovakia, and stop in Ottawa, Canada, to attend a conference of North Atlantic Treaty Organization and Warsaw Pact officials.

But the centerpiece of the secretary of state’s diplomatic excursion will be the START negotiations, where significant differences remain despite the large degree of agreement already achieved.

Both sides already have agreed to a limit of 6,000 nuclear weapons, such as warheads, for each side. Of these, a maximum of 4,900 could be carried on ballistic missiles, with the rest on air-launched cruise missiles (ALCMs) and in bombers.

Several other sub-limits of significance have been set. No more than 3,300 warheads could be carried on land-based intercontinental ballistic missiles (ICBMs), and no more than 1,540 could be on very large ICBMs. Only the Soviets have these “heavy” ICBMs, each of which carries 10 warheads.

Baker is expected to propose another sub-limit of between 700 and 1,000 warheads on mobile land-based missiles. The Soviets already have rail-mobile and road-mobile missiles, while the United States is preparing to build both types. But in case Congress allows neither, the Pentagon wants Baker to propose that all multiple warheads on land-based missiles be counted against the 1,540 limit on “heavies.”

Baker also will seek to nail down what has been a very elusive “counting rule” for ALCMs carried on bombers. The United States wants to attribute a fixed number of ALCMs to all bombers of a certain kind, such as 10 ALCMs on every B-52. The Soviets, in contrast, want to count all the ALCMs that each bomber is equipped to carry, such as 20 for the B-52.

The Pentagon strongly favors the U.S. counting proposal, in part because bombers seldom carry their maximum payload. Moreover, it does not know how many B-2 Stealth bombers Congress will allow it to buy. Those planes were to be used for penetration missions inside the Soviet Union. If significantly fewer B-2s are bought than initially planned, the military wants the flexibility to load more ALCMs on B-52s to make up for any B-2 shortfall.

Baker is expected to propose a compromise in which, if the Soviets accept the U.S. counting principle, the United States would accept Soviet demands for a greater limitation on the range of the ALCMs.

Moscow wanted all nuclear ALCMs with a range of more than 600 kilometers (375 miles) to be counted, while Washington wanted the range limit set at 1,500 kilometers (925 miles). A possible outcome, an official said, would be a slightly higher ALCM count, such as 12 for the B-52, in exchange for a range limit of 1,000 kilometers (500 miles) or even less.