Rough times for US Army's Pershing II

Superpower confrontation and Atlantic alliance relations are likely to focus during the coming year on a controversial US Army weapon of high cost and questionable ability.

This is the Pershing II intermediate-range missile, lead element in NATO's push to upgrade European land-based nuclear forces in response to the Soviet Union's growing advantage.

In recent months, the Pershing completely failed its first two test firings, and was less than fully successful on the third. Last week, the Army postponed the fourth scheduled test flight. Meanwhile, the missile's projected cost has doubled, and Congress, just before it adjourned, denied production funds until the Pershing II proves itself in further testing.

This not only puts the Pentagon in a bind, but is particularly disquieting to allied leaders faced with growing European public opposition to NATO's planned deployment of 108 Pershing IIs beginning about a year from now.

It also directly affects current US-Soviet talks over reducing theater nuclear weapons in Europe. The Soviets find the Pershing II - able to deliver nuclear warheads on Russian soil in just a few minutes - a particularly threatening prospect, perhaps more so than strategic nuclear weapons like the MX missile. American officials are sure the plan to deploy the Pershing IIs in West Germany has forced the Soviet Union to the bargaining table in Geneva.

Yet the credibility of NATO's 1979 ''two-track decision'' (theater nuclear modernization along with arms control negotiations) hinges on the missile working as advertised and being deployed on schedule. And today, both requirements seem less certain of being met.

The Pershing II will replace the 20-year-old Pershing I missiles under American command in West Germany. The newer missile is designed to have more than twice the range (about 1,000 miles), and be several times more accurate. It's designed to counter the Soviet SS-20, which carries three warheads and has three times the Pershing's range.

''Up to now, for all practical purposes, the Soviet territory has been a sanctuary,'' Maj. Gen. Niles Fulwyler, head of Army nuclear and chemical warfare programs, told a congressional panel during budget hearings. ''The Pershing II will offer, for the first time, the capability for theater nuclear forces to reach into the Western Soviet military districts.''

The purpose of this threat, in the view of NATO, is to deter a Soviet attack - conventional or nuclear - on Western Europe.

Originally, the Army intended to deploy the first Pershing IIs in late 1984, but the NATO plan moved that up a year. As a result, testing was accelerated (with the number of scheduled test flights reduced) and the Army asked to begin producing the missile before it was fully tested.

Earlier this year, the General Accounting Office issued a report titled ''Rushing Production of Pershing II Missile Could Reduce its Effectiveness.'' This has been a source of growing congressional concern, particularly as the missile's cost has grown. In less than a year, cost estimates doubled, and as a result the Army reduced the number of missiles it intends to buy from 39 to 21 with the 1982 appropriation of $194 million. The Army has ''stretched out'' the total production of Pershing II missiles from four to five years, which will add millions of dollars to the total cost.

One reason for increasing cost estimates is the growing complexity of the missile during development. During appropriations hearings, the Army reported that the number of parts in the missile had increased 15 percent to nearly 12, 000 and acknowledged that ''such things as parts count and number of parts types are considered to be good indicators of production cost.''

With all this in mind, lawmakers have thrown a wrench into production gears. In their recent funding bill they held up $493 million for 1983 Pershing II production until the missile successfully completes a test firing. The next such firing is scheduled to be conducted at White Sands, N.M., in January.

Meanwhile, the European allies are becoming increasingly restive over the future of the Pershing II. The Danish parliament voted to cut funds for support of missile deployment, and Pershing II opponents in Norway missed withdrawing support by a single vote.

Antinuclear forces are particularly strong in the Netherlands and Belgium, and West Germany rejected a US overture to double the 108 missiles planned for deployment there. NATO leaders remain committed to the two-track decision and the Pershing II, but this could change if the missile's troubles continue.