The status of forces agreement (SOFA) between Iraq and the US kicks into effect on January 1, and with it a significant shift in the relationship between the two countries.  Although US forces will still secure the Green Zone in Baghdad where government and diplomatic compounds are located, the Iraqis will have authority over it rather than the Americans for the first time since the March 2003 invasion.  The Iraqis are delighted, but some Americans are less so:

When the calendar flips to 2009 on Thursday, Iraq’s government will gain control over the Green Zone and its own airspace and some jurisdiction over security contractors under the terms of a deal that will fundamentally change how the United States operates here.

The changes, outlined in a landmark security agreement the Bush administration signed in November, are part of the broadest transfer of responsibilities to Iraqi hands since 2004, when the government regained sovereignty from the U.S.-led Coalition Provisional Authority (CPA).

The most visible changes will take place in the Green Zone, the fortified section of Baghdad that has been the U.S. headquarters since the invasion in 2003.

One change that the Iraqis wanted will create problems for American contractors — and perhaps indirectly for Barack Obama:

Until now, all American contractors have avoided Iraq’s jurisdiction under a rule issued by the CPA in 2004 that said contractors were “immune from Iraqi legal process.”

That arrangement has been deeply unpopular with the Iraqi public since September 2007, when guards from the Blackwater company opened fire and killed 14 Iraqis in Baghdad, according to the U.S. Justice Department. Five of the guards were indicted on manslaughter charges this month.

The SOFA explicitly ends that immunity for contractors working for the military or Defense Department. The agreement says nothing about contractors such as Blackwater that work for civilian agencies such as the State Department — and it is unclear how much their operations would be affected, if at all.

Blackwater and other contractors strenuously objected to that part of the agreement.  They do not wish to rely on Iraqi notions of justice and jurisprudence, especially in certain areas where their contractors have operated to protect American interests.  The State Department has warned the Pentagon and the White House that the Iraqis will almost certainly use that new authority quickly and that American citizens will soon find themselves under arrest in Iraq, which would force the departure of security contractors and others.

Blackwater does a significant amount of work in personal protection, and they usually hire retired or inactive service members for these tasks.  (Full disclosure: a friend of mine worked for a security company in Iraq.)  Their presence allowed the US to complete its mission with better security while deploying fewer troops by paying volunteers to serve through the private sector.  The wisdom of that policy has been under debate and will continue to generate controversy, but the fact is that their sudden departure will require a greater use of American troops to replace them.

Barack Obama promised a certain pace of drawdown during the presidential campaign, especially the primaries, although he retreated a bit on retreat during the general election.  If Blackwater and other security contractors decide to stop doing business in Iraq, the withdrawal will necessarily have to slow.  Troops designated for return home will have to get detailed to protection assignments for diplomats currently protected by contractors; Obama will not have the option of leaving them unprotected.  The other option — hiring Iraqi contractors — could prove disastrous, as the UN discovered when their security personnel helped attack their compound and killed over 20 of its staff.

The Bush administration will probably try to reach a quiet accommodation with Nouri al-Maliki, if one has not already been reached.  If that falls apart, either the State Department and the Pentagon will have to pay astronomic prices for security contractors or the Army and Marines will get longer assignments than Obama suggested.