US forces are expanding their numbers and activities in areas of Iraq controlled by two Kurdish political parties, signaling the opening of a delayed, scaled-down "northern front."
In the early hours of Sunday, four US planes landed at an airstrip just outside Sulaymaniyah and off-loaded "a couple of hundred" troops, mainly Special Forces, a senior Kurdish official told reporters on condition of anonymity.
For the Kurds, the Americans have been a long time coming. "Better late than never," says the Kurdish official.
It remains unclear just what the Americans intend to do from the Kurdish region. US news reports have indicated they may work in tandem with Kurdish militiamen to infiltrate the northern parts of Iraq that remain under the control of President Saddam Hussein, perhaps to "paint" targets for air strikes. They may also seek to foment uprisings in the northern Iraqi cities of Kirkuk and Mosul or play some role in protecting the region's oil fields from sabotage.
Analysts say that the US is most likely to use airborne troops to assault Kirkuk and Mosul after a more sustained and intensive bombing campaign than has been seen so far.
The landings on Sunday are not the only signs of increased US engagement in northern Iraq. In recent days US war planes have struck targets in the northern part of Hussein-controlled Iraq, principally in the cities of Kirkuk and Mosul.
Early Saturday, the US also initiated aerial attacks against two Islamist groups based in an eastern corner of Kurdish-controlled Iraq, an area that abuts the Iranian border. The US alleges that one of the groups, Ansar al Islam, has ties to Al Qaeda.
Ansar al Islam, thought to number some 700 fighters, has fought a civil war against the Patriotic Union of Kurdistan, which administers the eastern portion of the Kurdish region. PUK officials have long beseeched the US for military assistance, on the grounds that crushing Ansar comports with the US "war on terror" and would remove a source of distraction from the war against Iraq.
Small, secretive teams of US operatives have been in northern Iraq for months, but the Department of Defense only acknowledged their presence in northern Iraq last week. Reporters here have been able to spot the teams throughout the region - they travel at high speeds in trademark convoys of white SUVs with darkened windows. These operatives may have planned the airstrikes against the Islamist groups this weekend. Presumably the newly arrived forces will also contribute to this effort.
Sulaymaniyah is the capital of the PUK region, but the US is also expanding its presence in the area administered by the Kurdistan Democratic Party (KDP). Spokesman Fawzi Hariri said Sunday that the US forces would be arriving in greater numbers in the next "24 to 48 hours."
The delayed arrival of US troops in northern Iraq is largely attributable to Turkey. Pentagon planners had once envisioned sending tens of thousands of troops and heavy equipment through Turkey into northern Iraq, but the Turkish government refused, reflecting its public's near-total disapproval of cooperating with the US war effort.
So the US has had to settle for limited permission to cross Turkish airspace, and is using aircraft to bring much smaller contingents of troops into the Kurdish zone.
The debacle caused by the US attempt to win Turkish acquiescence remains unresolved. Turkey is insisting on its right to insert its own troops into northern Iraq during the war, ostensibly for humanitarian reasons. The Kurds fear that Turkey wants to roll back Kurdish autonomy - in order to dampen kindred desires among Turkey's Kurds - and have vowed to fight any Turkish intrusion.
US officials say they oppose any "unilateral" Turkish military role in Iraq, suggesting that continued discord lies ahead for Turks, Kurds, and the US.
While Kurdish officials may welcome the arrival of US forces, Kurdish civilians see cause for concern in the odd noises emanating from their skies.
Last week many Kurds fled cities and areas adjacent to the invisible lines that divide the Kurdish-administered areas from the rest of the country, fearing that the start of war might provoke an Iraqi attack.
No significant attacks have occurred, so some Kurds are now returning to their homes, seemingly convinced that war is unlikely to visit them personally. The arrival of US forces in larger numbers may change that.
In the mountain village of Kareza, an hour outside Sulaymaniyah, residents heard pairs of helicopters cross the sky late Saturday night and after daybreak Sunday. The village is a collection of 20 or so mud- and cement-brick houses set in the crease of a small valley dotted with cherry trees.
Galawezh Rashid, who came to Kareza on Wednesday from her other home in Sulaymaniyah, says she was frightened by the helicopters overhead. They were the first she has heard since the US buildup toward war began many months ago. "I wanted someone to turn off the generator so it would be dark and no one would see us," she says.