TURKEY, WHICH TALKS tough about terrorism, caved with regrettable ease to the four Palestinians who took over the Egyptian embassy in Ankara. The Turkish government agreed to allow the PLO, which negotiated the surrender of the gunmen, to open a permanent political office - a goal the PLO had sought in vain for years. Whether the government made any other concessions to the terrorists, who after killing three people were described by the prime minister as "the young people," is unknown. But the PLO came out with substantial advantages in image and in political coin.

This is unfortunate: Those advantages were not fairly earned. The PLO disclaims any connection with the four terrorists, who are said to belong to a small faction manipulated by the Syrians. Yet Syria supports and shares the PLO's rejection of the Egyptian-Israeli peace treaty. The PLO no less than Syria cranked up the anti-Egyptian fervor that led the gunmen to regard the Egyptian embassy as fair game. Certainly the PLO was not above drawing political profit from the episode. By negotiating the release of the surviving hostages in Ankara, moreover, the PLO has not set itself against terror in principle. It opposes terror only on grounds of political inconvenience.It thinks terror against Israel is fine.

The message the PLO ought to be receiving, especially from people and governments sympathetic to Palestinian self-determination, is to call a cease-fire and join the only political game going, the Camp David process. Political concessions made to the PLO outside of that context can only encourage it to stick to its policy of terror and nonnegotiation. To be sure, such concessions may serve the particular requirements of one or another nation's own foreign policy. That is the reason the PLO has no fewer than 90 offices in different countries around the world. But those concessions do not serve peace in the Middle East. It is hard to see how they even serve Palestinian nationalism. They are a trap, pointing the Palestinian movement toward a dead end.