Make no mistake - Turkey is not bluffing when it comes to the future status of northern Iraq.
Turkish soldiers have massed on Turkey's border with Iraq
The tens of thousands of Turkish soldiers on the border are not there just for show. The military observers accompanying American forces into Kirkuk are not simply a display of Turkish influence.
For months before the war began Turkey said it would not allow an independent Kurdish state to emerge from a post-Saddam Iraq.
Turkey assumed that the US would win a crushing victory, that Iraq's central authority would crumble and that the Kurds who have governed their own affairs in the north of Iraq would move south to fill a power vacuum.
One of Turkey's worst fears came to pass when Kurdish peshmerga took Kirkuk - the city is disputed, claimed by both Kurds and Turkmen, an ethnic group championed by Turkey.
But more importantly, it sits atop a vast well of oil, Iraq's third largest reserves and enough to make an independent Kurdish state economically viable.
Turkey has heard many promises before and remembers the breaking of them
No matter that the Kurds who run northern Iraq say they are not interested in independence, no matter that America has promised Turkey it will not allow a Kurdish state to come into being
Turkey has heard many promises before, and remembers the breaking of them.
It was promised much by the US before the first Gulf War and feels it received very little. It has watched and noted the way that the US has abandoned allies.
A war over Iraq and its oil may seem like a novelty to the West, but it was the Middle Eastern theatre of World War I - and its aftermath - that saw the last parts of the Ottoman empire, Turkey's predecessor, dismembered by the Allies.
The Turkish population is taught about such events from an early age.
Turkey protested loudly when Kurdish fighters took Kirkuk
So Turkey does not trust Britain and America, and it certainly does not trust the Kurds of northern Iraq.
In the mountains there are the remnants of the PKK, now called KADEK, the Kurdish paramilitary group which waged war against the Turkish state in the 1980s and 90s.
It was a war which became much bloodier when northern Iraq slipped out of Saddam Hussein's control following the first Gulf War.
For its part Turkey prosecuted the war ruthlessly - more than 30,000 people died, the majority of them Kurds.
Millions were thrown out of their villages and towns in the south east of Turkey as the military attempted to deny the PKK local support. There was terrible abuse of human rights.
If you think Turkey wouldn't flout international opinion by sending its military into Iraq, look at the way it fought the Kurdish insurrection, and think again.
Turkey believes that a Kurdish state would spark separatist sentiment only recently crushed, that once again its borders are threatened by events beyond its control, that the outside world does not care or understand.
Things are calmer since Kurdish forces started leaving Kirkuk.
But this is just the beginning of a long process.