General David Patraeus, commander Multinational Force - Iraq (MNF-I), and Ambassador Crocker are currently in Washington DC giving testimony to the U.S. Congress regarding the current state of the U.S. and Coalition occupation of Iraq. The purpose of this is to give someone without background some of the background behind the testimony. Actual analysis and especially implications on the current U.S. Presidential candidates belong elsewhere.
First, why is a senior General of the U.S. Army, and the commanding officer of the largest and most decisively engaged component of the U.S. military subject to questioning by a legislative committee(s). The U.S. has a strong tradition of civilian control of the military. In addition, the U.S. tradition is that the instruments of military power, are outside the political process. For many years, the U.S. military has emphasized as a point of pride, they were (are?) the only military in the world whose officer's swear their oath of service, not to a person or a group of people, but to a piece of paper (the U.S. Constitution). This is in marked contrast to the usual oath, which is to a head of state, a government body, or a political party. One of the ways that this plays out is both the executive and legislative branches can call on him based on their constitutional authority. And, the legislature can call on him without viewing him as an agent of the executive branch. And as all general officers are confirmed by the U.S. Senate, the Senate has some room to say that generals work for them. Not something that is used lightly, but in terms of providing testimony, the Senate can call on anyone they please.
Why Gen. Patraeus and not higher? The chain of command in the U.S. starts at the President, then the Secretary of Defense (a cabinet/ministerial level position). Then, the combatant commander (COCOM) (who is responsible for all military forces in the region) who then commands subordinates to implement policy. In the U.S., there is a parallel structure called the Joint Chiefs of Staff (JCS), who also report to the Secretary of Defense. The JCS are responsible for the training and equipping of forces. The COCOMs are responsible for how those forces are actually used. For U.S. forces in Iraq, as employed forces, their actions are under the perview of the COCOM (although their training back home is a JCS issue). In times of war, it is not unusual to appoint a theater commander (MacArthur, Ridgeway in Korea, Westmoreland, Abrams in Vietnam) responsible for all activities in theater, within the regional command. Patraeus is the regional commander for Iraq, within the larger umbrella of the U.S. Central Command.
Where did Patraeus come from? Regarding the current war in Iraq, Patraeus was a division commanding general during the initial invasion. Most accounts view him as very innovative during the initial combat operations, as well as in reestablishing civil affairs afterwards, something that was not viewed as typical. After return to the states, he was assigned to Iraq again in charge of training the Iraqi forces. He then returned to command the Fort Leavenworth and the Combined Arms College (a graduate level institution) at Leavenworth he and Marine General Mattis oversaw the writing of the new U.S. Army and Marine Corps Counterinsurgency doctrine. After this, Patraeus was selected to command MNF-I as the senior U.S. officer in the theater.
What is his relationship with the Bush administration? Well, pretty rocky over time. He has long been known as a counter-insurgency expert, and the Bush administration was very adament for a long time that the conflict in Iraq was not an insurgency. Some commentators thought that the assignment of Patraeus and others to the various military schools was essentially professional exile. (what kind of career does a military officer have as a college dean instead of commanding combat troops in a war). And with the Iraq war going very badly, the view of many commentators is that the Bush administration essentially cried for help, and brought Patraeus back to the war, even with his not very liked counterinsurgency doctrine. Because it probably would not do any worse. And Patraeus brought along a number of other officers who did a lot of thinking about counterinsurgency with him (and who had helped write the new counterinsurgency doctrinal manual). Somewhat of a return from exile.
Wait, I thought counterinsurgency and the 'surge' was viewed as the Bush great idea? Counterinsurgency (COIN) is still a very debated concept in the U.S. military, even among those who have recent experience in a war zone. One source of opposition are those who are concerned that the business of the army is to wage high intensity combat, the kind with tanks and artillery and mass formations. Not this COIN that is mostly done with small numbers in very close contact with civilians. Another group says that building up communities is not the military's job, so they should not learn how (the "we don't do nation building" crowd) and let the civilians do it. More cynical observers point to another source of opposition. Since COIN requires resources be put into training people rather then heavy equipment, cynics note that the normal military contractors don't get rich building tanks and planes in COIN, so they are opposed (along with their friends in uniform).
So, what is happening now in Washington? Gen Patraeus and Ambassador Crocker are back for a second round of testimony before congress. The first was in September 2007. Six months was considered to be a decent interval. As both of them are confirmed by the Senate, the Senate deals with them as their agents, (which is why Gen Patraeus had no need to discuss his testimony with the executive branch last September. The Ambassador is the President's personal representative overseas, so he probably does have some requirement to discuss with the President what he will say.)
The committees in question are the foreign service and the defense committees. This is where the real power in congress lies. The staff of these committees for both of the major parties are presumed to be experts in their fields, and are expected to prepare their members well regarding lines of questioning. But while they can give testimony regarding the current state of affairs in Iraq, as well as some discussion of options and what can be done with resources available (or made available), the actual current policy of Iraq is not really the topic of discussion. That comes when instead of listening to testimony, Congress is debating policy. And part of the purpose of this testimony is for the various sides to ask their questions and shape the policy debate to come. And to gather information and ammunition for that conflict to come.