ON JUNE 6th a premature report of a big Turkish invasion of northern Iraq rocked markets. Certainly thousands of Turkish troops, backed by tanks and artillery, have massed for a possible offensive against Kurdish PKK rebels in Iraq. Martial law has been declared in three of Turkey's Kurdish provinces. This follows rising violence against soldiers in Turkey. On June 4th seven Turkish soldiers died when Kurdish rebels raided an outpost in the province of Tunceli. In May six civilians were killed by a suspected PKK suicide-bomber in Ankara.

All this increases the pressure on Turkey's prime minister, Recep Tayyip Erdogan, to strike the PKK in its mountain strongholds in Iraq. General Yasar Buyukanit, chief of the general staff, has called a putative cross-border incursion “necessary” and “useful”. Deniz Baykal, the main opposition leader, is in favour.

But the American defence secretary, Robert Gates, said this week that the United States was squarely opposed to unilateral Turkish action, which would destabilise the only calmish bit of Iraq. The Americans would prefer the Turks to use the Iraqi Kurds to help them make peace with the PKK. The PKK itself wants to draw more Turkish forces into Iraq (the Turks have kept some 1,000 soldiers there since an incursion in the 1990s) because, as a source suggests, “this could provoke armed confrontation between Turkey and America.” It would also upset the European Union.

A few days before this week's alleged invasion, two American fighter jets had strayed from Iraq into Turkish airspace. The Americans said this was an “accident”, but some Turks saw a warning that America might side with the Kurds against them. Yet most Americans acknowledge that their refusal to heed Turkish calls to attack the PKK is now the main cause of rampant anti-Americanism in Turkey. Catching a few PKK ringleaders could improve matters.

The Iraqi Kurds are unwilling to co-operate mainly because they see the PKK as a bargaining chip to get the Turks to recognise their quasi-independent status in Iraq. The Turks are against a referendum in Kirkuk this December that might lead it to join the Kurdish region.

Massoud Barzani, the Iraqi Kurdish leader, threatens trouble in Turkey's mostly Kurdish south-eastern provinces, where his popularity is now starting to rival that of the captured PKK leader, Abdullah Ocalan. Most Iraqi Kurds consider their quasi-independent state as the real target of any Turkish incursion. But after two decades of battle, some 16 cross-border incursions and 40,000 dead, Turkey's leaders, military and civilian alike, know that force alone cannot solve Turkey's Kurdish problem.

The generals may have another reason for sabre-rattling. By insisting on government approval to strike in Iraq, they are shifting the blame for the violence to the Americans and the Iraqi Kurds—and to Mr Erdogan. With each Turkish casualty Mr Erdogan risks losing nationalist votes. Yet if he orders a full invasion, Turkey may just get bogged down and face new enemies.