Even before the dust cleared from the bloody scenes at a Baghdad market where at least 14 people were killed yesterday in a US-led air-strike, it was apparent that the Iraq war had taken a deeply disturbing turn. Coalition plans to advance on the capital are changing as US and British forces first deal with the resistance in the south that threatens key cities and has the potential to cut supply lines to the north. Implicit in the change of strategy is the fact that casualties - soldiers and civilians - will rise significantly. The gloves are coming off; cities that just days ago were to be 'liberated'' are suddenly 'military objectives'', raising the prospect of artillery strikes and street fighting. Disturbing reports were filtering in from the south - dozens of corpses surrounding bombed -out cars outside the town of Shatra, more than 650 Iraqis killed in Najaf. US naval spokesman Commander Ken Kelly captured the mood after examining the scene near Nasiriyah. 'It remains an unsecured town and a prime point for ambush by the enemy,'' he said. ''The numbers of Iraqi dead are very high. We saw at least a hundred bodies yesterday and I know that figure is much higher.'' As the bloodshed escalates, the pressures and the challenges before US President George W. Bush and British Prime Minister Tony Blair as they wage an internationally unpopular war emerge into stark relief. America has long insisted that it had learned the lessons of Vietnam and that, with the use of 'overwhelming force'' it would never again fight a war with one hand behind its back. And yet, suddenly, it raises questions of how large the death toll can get before the British and US publics cannot stomach any more. The impact on the Muslim world is already starting to be felt. As the terrible pressures mount, so does the harsh reality of war take over from the rhetoric that has driven months of diplomacy. In just a week, the coalition claims of 'shock and awe'' tactics and grand pledges to 'liberate the Iraqi people from tyranny'' have ebbed. In their place come complaints that Saddam Hussein's legions are not, of all things, fighting a fair fight. When Mr Blair and Mr Bush meet this morning (Hong Kong time), they must begin to reckon with the consequences of a strategy that has left them isolated internationally and in the not too distant future, perhaps, from their own publics. Both men implicitly promised their nations that the conflict would be quick and relatively clean, gambling their political careers as well as the lives of their troops on the outcome. One way out would be to resume engagement with the international community, by seeking a brokered arrangement with Baghdad. It might not look like the victory they seek, but it would be preferable to the continuation of an unworkable and unwinnable war.