UNITED NATIONS: If Rudy Giuliani's one-mayor crusade against poorly parked diplomats continues to escalate, New York's meter maids may find themselves up against a U.N. peacekeeping force. The U.N. Committee on Relations with the Host Country has given the State Department one week to make New York City's diplomat parking plan palatable to the world, or the issue will go before the General Assembly. "I don't think that would be very constructive," U.S. Ambassador Bill Richardson said today after the U.S. opposed the decision. "The U.N. would not look good." Under the city's new parking guidelines, U.N. diplomats must pay their parking tickets within a year or have all driving privileges revoked. Many of the 185 foreign missions in Manhattan say they instruct their diplomats to pay their tickets. But actually requiring it, they say, violates diplomatic immunity. During the often acrimonious debate, speakers from many countries claimed the city had failed to provide adequate parking for diplomats, and others complained that New York's finest single out diplomats' cars for ticketing, even when legally parked. A furious Giuliani called on Washington to resist. "What they are doing is intimidating the State Department," he said. "And the State Department shouldn't be intimidated. All you need is just a little bit of negotiating skill to figure out your way through this, which is to stand up to them, don't let them do this."