NATO tests weapons systems that bolster conventional defense

During its current Europewide military maneuvers, the Western alliance is fielding a number of major new weapons systems that vastly improve its ability to deter or fight a conflict.

NATO commanders have argued that only by improving their conventional arsenal and tactics to allow a counterattack on targets behind Warsaw Pact lines could they avoid using nuclear weapons as a last resort.

These additions to NATO's conventional inventory include sophisticated new AWACS, TR-1, and Nimrod ''spy planes'' and Tornado aircraft as well as British Challenger and German Leopard tanks.

The first two detection and command post aircraft are said to have greatly improved observation capabilities and therefore reduced what had been a worrisome deficiency over the ''warning time'' NATO would have of any mounting Warsaw Pact attack. These aircraft are an important element of the new US-backed strategy of counterattacking deep behind enemy lines that strategists claim would lower the likelihood of NATO resorting to nuclear weapons.

The tanks are the latest, and some experts say, perhaps the last, of the mammoth, heavily fortified, land combat vehicles. A debate is raging over the possible obsolescence of such costly 50-ton tanks, which may become increasingly vulnerable to smaller, cheaper, and more maneuverable vehicles or to man-held tank-killers.

These new military systems are part of the Western defense capability being tested during NATO's annual autumn exercises. This year they involve some 300, 000 military personnel along the front with the Warsaw Pact, from Norway to Turkey.

The AWACS (airborne warning and control system) has been discussed and in service since the mid-1970s. But it was introduced for duty in the NATO theater only in mid-1982. NATO has purchased 18 of the American-designed AWACS aircraft, and this is their first full field test with other elements of the NATO defense.

The TR-1, introduced in Britain in 1983, is actually the latest version of the well-known U-2 spy planes that have flown high-altitude intelligence missions over the Soviet Union since the early '60s.

Although some NATO planners are already pressing for newer reconnaissance and combat control systems, the AWACS and TR-1, along with the British Nimrod aircraft, have significantly boosted NATO capability in this sector, experts say. Former NATO commander Alexander Haig repeatedly warned of inadequate warning time for NATO forces before a Warsaw Pact attack. But his successor, Bernard W. Rogers, has rarely expressed such concern. Some of Rogers's staffers credit the arrival of the AWACS for the new-found assurance.

Experts say the AWACS and TR-1 fit well into General Rogers's proposed strategy of counterattacking deep behind Warsaw Pact lines to destroy enemy reinforcements and their support. He says this would lower the nuclear threshold in Europe by not forcing NATO to use nuclear weapons at an early stage of an attack as the only way to thwart a Warsaw Pact conventional invasion.

The new generation of British Challenger and German Leopard II tanks and the Tornado combat aircraft are credited by military officials as significantly bolstering the alliance's ability to counter a more powerful Warsaw Pact attacking force with only conventional weaponry.