PARIS: Richard Holbrooke Thursday tried to lower expectations that the weekend summit of Balkan presidents in Rome might produce any dramatic results. U.S. and NATO negotiators are trying to lower tensions sent sky high after the detaining of four Serbs the Muslim government accuses of war crimes. Briefing American reporters in Paris, Holbrooke said at least one hoped-for result would be a further clarification of the new 'rules of the road' governing the conditions under which NATO troops would take part in tracking down and arresting suspected war criminals. "The point of these rules of the road," Holbrooke said, "is to prevent authorities from just picking up people and then seeing if the Hague tribunal has anything against them." Paris bureau chief Thomas Sancton reports that NATO for its part seems ready to take a more active role in policing the Dayton police accord. "It appears that NATO is taking its earlier pledges more seriously, and is quietly giving more cooperation on such things as safe-guarding mass grave sites than it chooses to brag about." Sancton says that the NATO action apparently comes as part of a deal in which Muslims would agree not to arrest anyone that has not been formally charged with war crimes.