Irbil - Iraq's Kurds vote this month on whether or not they support independence for their enclave in the country's north, a step toward their long-held dream of statehood. The outcome, almost certain to be "yes", will further rattle a region still engulfed in the fight against the Islamic State group.A "yes" vote won't mean immediate independence for the Kurdish region since the referendum does not have legal force. But Kurdish officials say they will use it to pressure the Iraqi government in Baghdad to come to the negotiating table and formalise their independence bid.Already the September 25 vote is fuelling tensions. Baghdad and Iraq's neighbours, Iran and Turkey, which worry it will encourage their own sizeable Kurdish populations, have all demanded it be called off. Iraq's prime minister has called the referendum unconstitutional and warned of potential violence in territory claimed by both the Kurds and Baghdad. The United States, the Kurds' top ally, has tried to persuade them to postpone the vote, fearing it will open a new chapter of instability even as US-backed forces try to recapture the last remaining ISIS-held pockets in Iraq.The results could mark an important, historic shift. Since Saddam Hussein's fall in 2003, the Kurdish government has held off on dreams of statehood, saying it would try working within a united Iraq, albeit with a large degree of autonomy. A vote for independence would proclaim their determination to go it alone.If they eventually do break away, it would be the most significant redrawing of borders in the Middle East since the creation of Israel in 1948. It will split Iraq, tearing away a Switzerland-sized chunk, including key oil resources, and leaving the remainder with an Arab population split between a Shi'ite Muslim majority and Sunni minority. There are brakes on the Kurds' independence drive though, with many hesitant to break away without ensuring international support or recognition.