Leading article: Renewed bloodshed shows peace remains elusive in Iraq

The better news out of Iraq recently is not, as becomes increasingly clear, unalloyed. Provincial elections passed off peacefully last month. British forces in the south are likely to return home in the next few months, and security across most of the country has improved to the point where President Obama’s draft timetable for the withdrawal of US troops no longer looks over-optimistic. As we report, today, however, trouble is brewing in the one part of Iraq that has been spared the worst of the conflict over the past six years: the borderlands of the Kurdish autonomous region.

In fact, the areas around Mosul and Kirkuk have long been less stable than the relatively low level of violent conflict might have suggested. They were peaceful only in contrast to other parts of the country. Now, two developments are altering the dynamics. As central Iraq quietens down, unwelcome and redundant fighters are freed to turn their attention elsewhere, as are units of the Iraqi army. And with the United States set to start reducing troop levels, Iraqi Arabs and Kurds will face each other directly; there will be no third party either to keep them apart or mediate disputes.

The Kurdish region is often seen as an early success of the US invasion. In truth, it had been under international protection since the early 1990s, benefiting from the air exclusion zone mandated by the UN. Already autonomous to a significant degree and exempt from the predations of Saddam Hussein, it was in a better position to institute the democracy George Bush had envisaged for the rest of Iraq. As conflict engulfed the rest of Iraq, the Kurds prospered – and extended their sway.

It would be a sad paradox if the fortunes of the Kurdish region and the rest of Iraq were now to be reversed. But tension is increasing, as are kidnappings and killings. The issue is in part about territory, with the Kurds naturally reluctant to give up the territory they have expanded into over the past six years – territory which encompasses oil reserves. But it is also about culture, identity and pride.

One of the rarely spoken fears of the past 20 years, shared by many leaders in the region and beyond, was that the Kurdish region would announce a formal split from Iraq and declare itself independent. This was a particular nightmare for Turkey, with its large, separatist-minded Kurdish minority. But it was shared by Syria and Iran, both with Kurdish populations of their own. Even further afield, the possible arrival of a new state was widely seen as a threat that could foment instability far and wide. The US did its utmost to ensure that the Kurdish region remained inside Iraq; the price was autonomy that fell only just a little short of statehood.

If, as it appears, Kurds are now prepared to fight for the territory the Arab Iraqis claim as theirs, Iraq risks descent into fresh civil strife, but strife whose ramifications this time could extend far beyond its borders. Such an upsurge in violence that pitted Arab Iraqis against Kurds would inevitably place the question of Kurdish statehood back on the agenda, causing apprehension – or worse – once again in Turkey.

It would be a tragedy if peace elsewhere in Iraq had the effect of triggering another conflict, perhaps one even more dangerous than the first. But so long as cities such as Mosul and Kirkuk remain disputed, it is too early to declare the Iraq war over.