The U.S. and Japan reached aneleventh-hour agreement in time to avert a potentially devastating trade war. In announcing the deal, a jubilant President Clinton said "This agreement is specific. It is measurable."Japan will yield on the major sticking point of the negotiations, taking steps to open its markets to American auto manufacturers.While U.S. officials describe the deal as "historic,"TIME Detroit bureau chief William McWhirtersays its impact remains to be seen. One key point: will the $9 billion in new Japanese purchases of American auto parts -- which in Japan cost less than half the price of parts made by Japanese companies -- apply to cars made in the U.S., or to cars made in Japan? Trade officials have not yet clarified that point. "The fact that the negotiators finished early, with a lot of goodwill on both sides, suggests this is more than a face-saving move and could be a major breakthrough. But, we will have to see how it plays out over the next few years, and just how far it goes in opening the Japanese market to American autoparts manufacturers, before we can call this a historic opening."