While I do not discount the longstanding animosity between Turks and Kurds causing an unfortunate engagement, I do doubt the Turks will actually mount a major cross border incursion. Having a low level border viloation omething that they can explain away as an "oops, sorry I didn't mean to cross the border but I was in hot pursuit of these PKK bad boys ," seems well within the range of the posible. What I cannot speak to is the reaction by the folks on the Iraqi side of the border. Given the amount of Turkish investment into the Iraqi Kurds' economy, there may be a lot of room for maneuver.