As Turkey's parliament considers military action against Kurdish guerrillas in northern Iraq, BBC world affairs correspondent Nick Childs looks at the tensions the move is causing and the possible regional implications of military action.
Already, ahead of time, the move in the Turkish parliament is prompting a new flurry of diplomacy - and maybe that is the main intention.
But Ankara knows Iraq's central government has little clout in the largely autonomous Kurdish north of the country.
Even a small raid could carry big risks
The Turkish Prime Minister, Recep Tayyip Erdogan, has played down the prospect of any imminent action. Western military sources also say there are no obvious preparations under way for anything big.
But such action would be popular in Turkey. Any major incursion would clearly have significant implications.
The Turkish military might limit itself to small raids, even possibly just air strikes, which might have limited repercussions.
Yet they too would carry risks. Anything which looked like presenting a threat to the city of Kirkuk and its nearby oilfields could provoke a major crisis, which could suck in Iraqi forces, the Americans, maybe even the Iranians.
Clearly, Washington is worried. It does not have the resources to take on further military challenges in Iraq. It is also hugely dependent on Turkish support for its presence there anyway.
And Turkish-US relations are already going through a very difficult phase, complicated by a vote in a US congressional committee condemning the mass killing of Armenians in Turkey in World War I as genocide.
Perhaps conscious of the risk of a rupture in relations between Washington and Ankara, support for the motion in Congress now seems to be waning.
It is a complicated set of calculations for the authorities in Ankara, too, as they try to position themselves in what is a region in flux.