On July 4th, US forces operating in northern Iraq's Kurdish zone raided a compound near Sulamineyah. The US forces arrested 11 Turkish special forces troops. Suddenly several unsubstantiated stories hit the wires, including an allegation that the Turkish special ops troops were planning an assassination in Kirkuk. A subsequent report described the "compound" as a locally known "office" used by the Turkish military (ie, it wasn't a secret the Turks were there). The arrests precipitated an immediate and very real diplomatic crisis between the US and Turkey. The US vice-president and Turkey's president were involved in the discussions. Turkey threatened to deny the US permission to use the big NATO air base at Incirlik. That would put a crimp in US operations, given Incirlik's extensive facilities. However, Baghdad International is increasingly able to handle support flights. Turkey claimed the special ops personnel had the right to be there. Several of  the troops were released on July 5. Turkish troops have long operated in northern Iraq against the PKK and have bases inside northern Iraq.