The United States has declared war on terrorism, but just who are the terrorists?

Take the Israeli-Palestinian conflict, says Martin Indyk, a former U.S. ambassador to Israel who is now a senior analyst at the Brookings Institution. What to Israelis are terrorists are freedom fighters to Palestinians.

"We say that there is no distinction between good and bad terrorism. They say that Palestinians are fighting to end the occupation, not conducting terrorism. While we say that the Palestinian suicide bombers are homicide bombers killing innocent people, they say that it is Israel that is the terrorist," Mr. Indyk said.

Speaking at a conference held by the U.S. Institute of Peace, former national security adviser Brent Scowcroft said as often as we mention al-Qaida, we are not sure what it is. Maybe we should not even give it a name.

"That probably is too formal. It is much more shadowy than that. It is sometimes owned by al-Qaida. In some places it is just local malcontents, whom al-Qaida trains, uses, teaches them how to falsify documents, all those kinds of things," Mr. Scowcroft said.

Al-Qaida, though prominent, is only one of the world's terrorist groups, said Mr. Scowcroft. Each pursues its own destructive goals, and must be treated accordingly. No one strategy can cope.

"There are all kinds of terrorism. They are all repugnant, and we need to deal with them all. We cannot deal with them all at once. Making all terrorism equal dissipates our ability to concentrate and makes the problem, if we take it seriously, almost unmanageable," Mr. Scowcroft said.

It can only be managed with international cooperation, said Paul Pillar, former deputy chief of the CIA's Counter-terrorism center. "Bearing in mind the transnational nature of the adversary and the informational, jurisdictional and geographic advantages that our foreign partners so often have, much of what we do in counter-terrorism is only as good as the ability and willingness of our foreign partners to cooperate," Mr. Piller said.

A clear victory over terrorism will not be seen, says Mr. Scowcroft. There will be no formal surrender. It is embedded in the times, the tendency for societies to break up into smaller, more homogeneous entities that view the rest of the world with increased hostility.

But with proper tools and improved intelligence, with patience and perseverance, says Mr. Scowcroft, we can reduce terrorism from a paralyzing influence to a bearable nuisance.