NEWS ANALYSIS : U.N. Commander in Bosnia Sidesteps Use of Force to Punish Cease-Fire Violations : Peacekeeping: Evidence suggests that the conflict is escalating. Diplomats worry that the world may assume things are on the mend.

On days when Bosnian Serb rebels have allowed U.N. troops to patrol the mountainous terrain around Sarajevo, the peacekeepers have counted at least 20 heavy artillery pieces and seven tanks in violation of a NATO-proclaimed no-weapons zone.

Despite a threat made more than three months ago to punish such violations with air strikes, the U.N. Protection Force is still trying to win withdrawal of the offending Serbian armor through negotiation.

In the eastern enclave of Gorazde, the U.N. mission has set aside another NATO ultimatum.

Serbian gunmen who invaded the U.N. “safe haven” in April have refused to heed a U.N. order to retreat. But instead of ordering air strikes, the mission has asked the Bosnian government to make a “goodwill gesture” to encourage its attackers to pull back.

The U.N. commander for Bosnia, British Lt. Gen. Michael Rose, has asked the Muslim-led government to withdraw its lightly armed defense forces from the center of Gorazde--an act of capitulation requested neither by NATO nor by the U.N. Security Council.

Rose insists that the threat of air strikes against those defying the international community’s efforts for peace is still credible.

But with mounting evidence that the mission has neither the will nor the political backing to use force against transgressors, cease-fires have broken down, fighting has escalated, and U.N. officials have adopted a damage-control strategy that oscillates between understatement and outright denial.

U.N. mission spokesman Maj. Rob Annink has begun each daily briefing for the last week by describing the situation in Bosnia-Herzegovina as “stable,” while subsequently reporting the following incidents:

* Serbs fired at least 500 artillery shells into the mostly Muslim enclave of Bihac, another U.N.-protected area, in the 24 hours before Thursday morning.

* Government forces have been on the offensive against Serbs in the central Bosnian town of Tesanj, as well as in Olovo and along 100 miles of front line that arcs between the two flash points.

* Bosnian Croats and government troops have massed on either side of the narrow Serb-held corridor linking conquered areas of eastern Bosnia with Serbian spoils farther west. The Croats and Muslims, newly reconciled allies, appear to be coordinating artillery attacks on the town of Brcko, along the vital supply route.

* Two Serbian tanks entered the weapons exclusion zone around Sarajevo on Monday to attack government forces in the town of Breza. Another Serbian assault Wednesday against the government town of Pazaric was also suspected to have been launched from the zone, which is supposed to be demilitarized.

* On Tuesday, snipers killed a Bosnian woman riding a bus under U.N. escort through Serb-held territory west of Sarajevo. Bosnian government officials said she was at least the 40th civilian fatality since NATO proclaimed a cease-fire in the area three months ago.

Sarajevo has not been under intense bombardment since the February ultimatum, but sniping remains a daily danger, and there have been increasing instances of “detonations” that the U.N. spokesman refuses to call shelling.

Foreign diplomats in Sarajevo express concern that Rose’s not-to-worry approach to collapsing cease-fires and fraying agreements is giving the outside world the erroneous impression that the conflict in Bosnia is on the mend.

“On the one hand he is putting pressure on the parties to settle this thing diplomatically, by refusing to publicly acknowledge what is going on,” one European envoy said. “On the other hand, he’s taking a tremendous risk of it all blowing up in his face, as it did in Gorazde.”

Rose repeatedly characterized a recent Serbian offensive against that safe area as a “limited, tactical maneuver” to improve the rebels’ bargaining position in stalled peace talks.

But nearly half the city fell to Serbian gunmen, tens of thousands of Muslims were uprooted, and 700 people, mostly Muslim civilians, were killed in the sustained artillery attack.

Another Western diplomat characterized the U.N. mission’s attempt to play down the spreading crisis as a consequence of the world’s major powers having given the peacekeepers no real option for containing it.

“There’s this assumption that Bosnia is already dead and it just needs a proper burial,” the diplomat said. “The problem with that assumption is that Bosnia is not dead, and it’s going to continue fighting.”

Rose warned the Bosnian army Tuesday that it should not pursue a military solution to the conflict.

While shepherding a NATO delegation around some of central Bosnia’s more peaceful venues, Rose told a senior army commander that it would take years for the government to get its troops armed and trained for a successful campaign to recover lost territory.

Government officials say they resent the attitude that they should accept defeat by a force castigated by the U.N. Security Council as the war’s instigator.

“The problem is that the basic aim of the mission from the beginning has been to see us capitulate,” Bosnian Information Minister Ivo Knezevic said. “All their calculations have been based on this assumption. We’ve blown all their plans because we do not accept this. This is why we have become such an irritation to the powerbrokers of the world.”