NEWS ANALYSIS : After Air Strikes, NATO Would Never Be Same : Bosnia: The first salvo would change the nature, structure and scope of the alliance, senior officers say. It was conceived as a defensive partnership.

While diplomats wrangled and snow fell on anguished Sarajevo last week, NATO planners here wrote combat orders for a mission that would launch the 16-nation alliance into uncharted waters.

A U.S.-West European partnership that stared down the Soviet bear for over 40 years without firing a shot prepared with exquisite detail to unleash a fearsome armada of planes against any Serbian gun positions still besieging the Bosnian capital.

Their first salvo would change the nature, the structure and the scope of the alliance that won the Cold War, senior officers say.

NATO forces poised this morning on three aircraft carriers in the Adriatic and bases in Italy are meant to be intimidating. They are also deadly. The outcome is not at issue if the jets fly against the guns once a get-out-of-town ultimatum expires at 4 p.m. Pacific time today.

“I’d rather have my job than the job of a ground commander who was trying to shoot artillery at Sarajevo, or to hide,” said U.S. Adm. Jeremy Boorda, who commands NATO’s southern forces at their headquarters here in the gritty Naples suburb of Bagnoli.

To avoid NATO attack, the warring sides must have surrendered their heavy weapons or have removed them 12 miles from the city by the deadline. For the last three days, they appear to have been making an effort to do so.

Boorda’s confidence in an interview last week was echoed by NATO officers here who were struck by the unprecedented role that the alliance had accepted: armed guarantor of the United Nations.

“There’s been nothing like this for over four decades of NATO,” one senior officer said on condition of anonymity. “And the difference is even greater for the Americans. Having delegated authority, the White House and the Pentagon remain vital participants, but they’re not the principal actors once shooting begins.”

Air strikes by U.S., French, British and Dutch jets representing an alliance born in the shards of World War II would stir immediate international echoes both novel and far-reaching.

They would signal:

* NATO’s first resort to violence.

* An offensive strike by an alliance conceived and grown to maturity as a defensive partnership to guard against outside aggression.

* The use of offensive violence outside the territory of one of its members, never contemplated by NATO founders.

Just as groundbreaking to American officers here at a polyglot base where partners’ uniforms are as different as the cultures they represent is that Bosnia has forced the jettisoning of a hallowed military principle.

“There’s no Stormin’ Norman this time; there’s no unity of command,” said an American officer who remembers allied commander Gen. H. Norman Schwarzkopf from the 1991 Persian Gulf War.

Rather, the Bosnia collaboration between the United Nations and the North Atlantic Treaty Organization hinges on a dual, parallel command structure.

On the U.N. side, authority runs down from Secretary General Boutros Boutros-Ghali to Yasushi Akashi, the U.N. special representative for the former Yugoslav republics.

Akashi coordinates with French Gen. Jean Cot, commander of the peacekeeping U.N. Protection Force for the former Yugoslav federation. From his headquarters in Zagreb, Croatia, the French officer confers with British Lt. Gen. Michael Rose, the U.N. commander in Bosnia.

On the NATO side, Secretary General Manfred Woerner, a German, sits atop the North Atlantic Council, the alliance’s highest political body. The council agreed last April to enforce a much-ignored U.N. ban on fixed-wing flights over Bosnia-Herzegovina.

NATO Operation Deny Flight began April 12, 1993, with U.S. Air Force and Navy jets first among alliance equals over Bosnian skies--as they would be in any attacks. In June, NATO foreign ministers agreed to provide close air support to U.N. troops in Bosnia if requested.

Acting within the framework of U.N. resolutions, in August the NATO council ordered planning for air strikes to break the Bosnian Serb stranglehold on Sarajevo, and for possible action against large-scale interference with humanitarian assistance.

U.N. commanders have so far not asked for that intervention, but in January, NATO heads of government, President Clinton among them, affirmed their readiness to use force under authority of the U.N. Security Council.

On Feb. 9, the NATO council authorized Boorda as commander of Allied Forces Southern Europe to mount air strikes at U.N. request against artillery or mortar positions around Sarajevo responsible for attacks on civilians. It also set the 1 a.m. Monday Sarajevo time deadline in coordination with the United Nations.

Mostly air-to-air fighters at the start of Deny Flight, NATO aircraft are by now strongly reinforced with fighter-bombers, attack planes and gunships for close air support. The NATO air force is commanded by U.S. Lt. Gen. Joseph W. Ashby from headquarters here, while day-by-day operational control is directed by Italian Lt. Gen. Antonio Rossetti at Vicenza, in northern Italy.

Overall planning and command comes from here in Naples under Boorda, a four-star admiral who is also commander of U.S. naval forces in Europe.

In the last 10 days, a net of NATO-U.N. cooperation has been woven in a Naples-Zagreb-Sarajevo triangle. Four times Boorda and aides have flown to Zagreb to confer with Cot and Rose.

“What it comes down to if the bell rings is Rose-to-Boorda-to-the-pilots,” one senior officer said.

It is the pilots, the sharp end of NATO’s stick, who represent another novelty in preparations for any assault.

“In the Gulf, intelligence officers told attacking units what to expect. This time, the pilots know better than anybody at headquarters what Bosnia’s like--they know it like the back of their hands,” said a U.S. officer.

Since last year’s air embargo, NATO pilots have made more than 11,000 flights over Bosnia, 7,000 of them in the sort of aircraft that would attack the guns.

The pilots also have trained extensively with U.N. forward observers in the hills around Sarajevo.

“By now many pilots and observers are on a first-name basis--and they both know where the guns are,” one officer said.

If the cards seem stacked, they are--even without counting friendly technology.

What NATO planners call “the warring factions” in Bosnia may scowl at one another through binoculars. NATO is wed to in-flight electronic wizardry. Thanks to it, commanders at sea and on land can see all of Bosnia in real time on their desktop computers.

“If the order comes to fly, we’ll have done all we can to minimize the fog of war and the strangeness of the place,” a senior American officer said.