FEARFUL of being sucked into a quagmire, NATO commanders in Bosnia are ignoring increasingly flagrant violations of the Dayton peace accord.
NATO's high-risk tactic, observers say, either sets a new precedent for prudent peacekeeping or emboldens extremists on both sides to try to destabilize the situation.
Much of what has occurred in Bosnia over the last week is eerily reminiscent of the failed United Nations peacekeeping mission in the former Yugoslavia:
* A Bosnian Serb sniper wounds two passengers on a new bus service linking the government-held and Serb-held parts of Sarajevo Wednesday. NATO troops do not respond to or investigate the incident, calling the buses ''a local police matter'' to be investigated and protected by Bosnian Serb officials.
* A Muslim journalist is arrested by Serb police in a Sarajevo suburb that technically went under the control of the Muslim-Croat federation on Jan. 19. But the neighborhood remains clearly under de facto Serb-control. Ten days later, UN officials are ''pressuring'' the Serbs to release him, NATO refuses to get involved, and the photographer is being investigated for charges ranging from espionage to war crimes.
* Three days after the Muslim-led Bosnian government refuses to abide by a US-brokered agreement and release four lower-ranking Bosnian Serb soldiers, the Bosnian Serbs reportedly seize four Muslims in another part of Bosnia in retaliation. UN and NATO officials, citing vague language in the Dayton peace accord, say suspected war criminals can be seized and held by each side for an undetermined amount of time.
NATO spokesmen say sniping incidents and arbitrary arrests are ''policing issues'' not for NATO's involvement. Eager to exit Bosnia with as few casualties as possible in an election year, the Clinton administration is allowing NATO military commanders to interpret their responsibilities here as narrowly as possible.
Western officials warn that respecting the authority of Bosnia's warring parties was exactly what NATO's muscular peacekeeping mission was not supposed to do. They warn that if NATO forces do not deal with violations now, they will face far more dangerous violations that could result in NATO casualties in the future.
NATO forces are being held back from being drawn into minor tasks and the only alternative is a much-delayed UN police force, which is unarmed. US officials involved in drafting the Dayton accords say they anticipated the problem, but their European allies - who would be largely responsible for manning the police force - don't want to risk their people.
''We've known from the beginning that the UN police were the weak link,'' says a senior American diplomat.
The same concern about casualties that doomed the UN mission here is being repeated, Western officials warn.
The incidents this week show that enough goodwill may not exist on the part of the two sides for peace to be implemented without force being used.