President Bush has vowed to wage war against the underworld of terrorism and to "make no distinction" between terrorists and those who harbor them.

If he means this -- if he truly intends to rid the world of this increasingly dangerous scourge -- then his quest cannot end with Osama bin Laden. It must extend to others. And that includes Palestinian leader Yasser Arafat.

No one on Earth, not even bin Laden, has been involved in terrorist activities for a longer period of time than Arafat. He is guilty on both counts of the president's indictment: He has directed terrorist assaults, and he continues to harbor terrorists.

We are living a fiction if we ignore these facts. For years, Arafat has played the role of peacemaker, all the while hiding and encouraging those -- the terrorist group HAMAS included

-- who kill innocent civilians for sport. He has acted as if he were trying to end the strife with our friends in Israel, but he has never wavered -- not once -- from his plan to destroy it.

Arafat's "government," funded and armed largely by the United States, consists of cronies who keep their people in poverty, apply justice arbitrarily and make common cause with the Middle East's worst elements. If we are serious about eliminating the hydra-headed monster of international terrorism, we must recognize that Arafat is part of the problem, not the solution.

Arafat can't shift the blame. He can't claim the terrorists carry out their bombings of restaurants and shopping malls independently. When he says stop, they stop. It only makes sense that when they go, they act, at the very least, with his blessing.

Ehud Barak, former prime minister of Israel, wrecked his political career trying to appease Arafat. He was prepared last year to sign away most of Jerusalem, all of the West Bank and some of Israel proper. He was ready to let Arafat form a state that would have been, from Day One, hostile to his own.

If "land for peace" -- Arafat's mantra -- carried any real meaning, Arafat would have agreed to that deal. But he couldn't, because the people he represents want no deal with Israel, no peace. To them, the Middle East conflict ends only when the blue-and-white flag with the Star of David flies no more.

At least some Israelis know better than to believe Arafat. When he promises to round up those who commit terrorist acts, he either never does, or he has them detained for only a couple of days. He has done little to stop the 200 or more known terrorists who operate under Palestinian Authority cover -- several of whom continue to serve in the Palestinian security services.

Under the 1993 Oslo accords, Arafat's police forces were limited to 30,000 men. Their weapons were limited to light arms provided by Israel and the United States. The force now consists of more than 50,000 men, and mortars, rocket-propelled grenades and heavy machine guns that are used routinely to attack Israel.

Arafat's fight has become a parochial sideshow to the fight America now prepares to wage against terrorism. Benjamin Netanyahu, another former prime minister, says the bin Laden gang views Israel more as an instrument of Western decadence than the blood enemy it represents for Arafat.

But terrorism is terrorism, and no one practices it more expertly than those who do Arafat's bidding. He's never going to be an instrument of peace. And President Bush is never going to eradicate terrorism until HAMAS and the other terror cells that operate under Arafat's protection are eliminated.

Edwin Feulner is president of The Heritage Foundation, a Washington-based public policy research institute.