Fifteen years ago, an American president confronted a great evil and found a simple and powerful way to call for its undoing.

Defying his panicky State Department, Ronald Reagan used the Cold War backdrop of the Berlin Wall to call on the leader of the USSR to terminate the Evil Empire. "Mr. Gorbachev, tear down this wall."  The rest is history.

Today, President Bush has an opportunity to herald a similar call as he confronts an evil to which he is no less passionately opposed than was President Reagan to communist totalitarianism: the determination of many in the Arab world to pursue the complete destruction of the state of Israel.

Soon, the president may instruct Vice President Dick Cheney to return to the Middle East to help give a fresh start to efforts to achieve a genuine peace between Israel and its foes.

A big problem, however, is the map.

There is reason to believe that most Arab states are no more serious about making a genuine peace with Israel now than they have been in the past. To the contrary, many in the Arab world and among the Palestinians in particular clearly believe the time is ripe to "liberate" not only the disputed territories captured by the Israelis in 1967, but all the land "occupied" by the Jews — including all pre-1967 Israel.

They sense that, as in Lebanon, their violence is paying off, driving the Jewish "crusaders" off disputed land and hammering a wedge between Israel and her most important ally, the United States.

This was the goal of Mr. Arafat's Palestine Liberation Organization when it was established in 1964 — that is, before Israel had "occupied" any territory on the West Bank or Gaza. And so it remains today. However, in the wake of the Arab armies' 1973 defeat the last time they tried to destroy Israel, the PLO decided that the ultimate objective would have to be achieved in stages.

This approach was formally adopted in 1974 and became known as the "Plan of Phases": In the first phase, Israel would be compelled to relinquish territory that could be used subsequently to drive the Jews into the sea.

Hence the map. The unwavering commitment to this goal has long been reflected in a map of "Palestine" widely used by the Palestinians and other Arabs. In it, Palestine consists of not only all of the West Bank and Gaza Strip, but all of pre-1967 Israel, as well. Accordingly, there is no Israel at all on the maps used in Mr. Arafat's offices, on the uniforms of his paramilitary "police" or on the Web site of the Palestinian National Authority and its agencies.

Most insidious, perhaps, is this map's repeated appearance in the textbooks with which the next generation of Palestinian schoolchildren are taught to think about their birthright — and shaped in their expectations about a future homeland.

A halfhearted effort has lately been made to claim this map as a depiction of an historical nation known as Palestine. This is a fabrication. In his recently re-issued and authoritative work, "Islam in History," Bernard Lewis — one of the most eminent scholars of Mideast history — makes clear that there has never been a Palestine with the boundaries shown on Mr. Arafat's map.

Under these circumstances, Israel is fully within its rights to resist appeals to surrender land its enemies have used in the past to try to destroy the Jewish state. Indeed, it would be the height of folly and possibly state-icidal to do otherwise. Neither Israelis nor Americans whose national interest is served by having a strong, secure and self-reliant democratic ally in the Middle East can responsibly ignore this reality.

Consequently, if President Bush wishes to play a constructive role at this difficult moment in the Mideast, he must insist that Israel's adversaries stop paying lip-service in English to their desire for peace while cultivating the intolerance and destructive propensities that endanger our ally and preclude it from safely considering further territorial or other concessions.

A good place to start would be issuing a call much as Ronald Reagan did a generation ago: "Mr. Arafat: Renounce this map" — and ensure that neither the Palestinian Authority nor its friends any longer use such representations to describe an end-game for the so-called "peace process" with which Israel literally cannot live.

Frank J. Gaffney, Jr. held senior positions in the Reagan Defense Department. He is currently president of the Center for Security Policy.