In its startling and sudden reversal of a long-standing policy of refusing to talk with the Palestine Liberation Organization, the U.S. this week may have made a historic breakthrough toward building bridges to peace in the Middle East.

Some observers have called it the most significant move in the region since the signing of the Egypt-Israeli peace pact in 1978. Like the peace pact, it breaks a logjam that has existed for decades.The timing and reasons for the change are murky and confusing, especially as they were linked to PLO leader Yassar Arafat's comments in Geneva, Switzerland - comments at first criticized by the U.S.

Arafat's speech before the United Nations' General Assembly in Geneva - was moderate in tone and called for peaceful settlement of Middle East differences, but was rejected by the U.S. because it wasn't "explicit" enough about the PLO renouncing terrorism and recognizing Israel's right to exist.

But some of the problem may have had to do with translations from a foreign language. In any case, a subsequent news conference by Arafat "clarified" his remarks. Not much appeared to have changed and certain items were as vague as before, but suddenly, the U.S. announced itself satisfied.

But these details are of small moment alongside the reality of what has happened.

On the surface, all that has really occurred is that American representatives will sit down in face-to-face negotiations with the PLO. In fact, the talks already have started. In agreeing to talk, the U.S. is not "recognizing" the PLO in a diplomatic sense. Neither is it recognizing the new Palestinian state being promoted in the Israeli-occupied territories.

The U.S. is merely a mediator, not the one who decides. Other Middle East states, particularly Israel, will have to make the final decisions. And it must be emphasized that sitting down to talk is not the same thing as coming up with the answers. The problems are deep and complex, intertwined with history, religion, homelands, conflict, and hatreds. Acceptable solutions will still be very difficult to achieve.

The U.S. decision to meet with the PLO has profound implications for Israel. Israelis are faced with the fact that negotiations regarding their future are about to begin between their best friend and sponsor and their sworn enemy.

That can't be a comfortable feeling for hard-line Israeli leaders who said only this week they would never negotiate with the PLO, with its long record of terrorism. Yet U.S. Secretary of State George Shultz says the American objective is to bring about direct talks between Israel and the PLO.

Israel's problems are complicated by the fact that the country remains without a new coalition government following its recent elections that divided the vote almost equally between the two major parties.

There are still grounds for being concerned about the PLO. Despite Arafat's seeming renunciation of terrorism, the PLO remains a loose umbrella for all kinds of groups, including some radicals determined to destroy Israel no matter what the cost. What if Arafat can't keep his colleagues in line? For Israel, not just politics but the country's very survival is ultimately at stake.

But at this point some limited risks certainly seem worth taking. Talking is almost always better than fighting; simply refusing to budge cannot solve anything. An opportunity has opened up that may lead to a settlement of a previously intractable problem. It would be folly not to seize it.