Several thousand Turkish troops along the Iraqi border are, to the Kurds of northern Iraq, acting like an invasion force. The Turkish units do occasionally move into Iraq when pursuing Kurdish rebels, and the Iraqi Kurdish troops just stand aside. Turkey also has had 1,500 troops inside northern Iraq for years. The Iraqi Kurds tolerate that as well. But several thousand more Turkish troops entering Iraq, even if temporarily, is another matter. Turkey wants the Iraqi Kurds to round up the Kongra Gel and al Qaeda Kurds in northern Iraq. The Iraqi Kurds don't want to lose a lot of people fighting fellow Kurds, and don't want to allow the Turks to do it. But the pressure is building up and something's got to give.