Absolutely the last thing Iraq needs right now is to have thousands of Turkish troops pour across the border into the country’s one relatively peaceful region — the Kurdish-administered northeast. Turkey’s government needs to know that it will reap nothing but disaster if that happens. A huge military build-up is already under way on the Turkish side of the border, and Ankara has been issuing a flurry of angry charges that the Iraqi Kurds are providing sanctuary to murderous anti-Turkish guerrillas.

The Bush administration has rightly stepped up its warnings to Turkey not to attack. A Turkish invasion would not only embarrass the US, which numbers the Kurds among its few allies in Iraq. It would add a whole new and even more dangerous dimension to the mess in Iraq. It would infuriate Arabs, who would resent any Turkish return to areas once ruled by the Ottoman Empire. It would finish off any remaining hope of Turkey joining the EU. And it would put a huge strain on Turkey’s fragile democratic politics. In short, it would be a disaster.

Reining in the Turkish Army will take more than US warnings. Turkey’s leaders must understand that a major military operation in Iraq could touch off a series of regional wars and realignments that would harm Turkey more than anything the PKK could possibly

cook up.