Excellent post, much of which I completely agree with. My sense is that domestic political considerations are almost wholly driving this election's rhetoric on Iraq and Afghanistan. What I mean is that the policy perscriptions are largely based on appeasing certain electoral demographics within the US as opposed to being based on genuine US regional interests. This thesis is reinforced, I think, by the paucity of detailed information on what candidates would actually do and the clever use of language in their rhetoric which will give them a wide latitude of action once they achieve office. I therefore don't believe either of the Democratic candidates will "end the war" in Iraq nor do I believe that McCain will ultimately pursue "victory" as it is currently defined.

As George Friedman of STRATFOR recently wrote:

The consensus on foreign policy is the most interesting feature of the election, especially regarding Iraq. We don’t mean the posturing or the shouting or the attempt to position one candidate against the others. We mean two things: first, what the candidates are saying after the passion is boiled away, and second, what they are likely to do if they become president.

There is, of course, a great deal of discussion about who supported or opposed what and when. That is not a trivial discussion, but it doesn’t really point to what anyone will do. On a second level, there is the discussion about whether the United States should withdraw from Iraq. Even here, there is actually little that divides the candidates. The real question is when that withdrawal should take place, over what period of time and whether the timeline should be announced.
And,

It has long been said that presidential candidates make promises but do what they want if elected. In foreign policy, presidential candidates make promises and, if elected, do what they must to get re-elected. Assume that the situation in Iraq does not deteriorate dramatically, which is always a possibility, and assume a president is elected who would simply withdraw troops from Iraq. The withdrawal from Iraq obviously would increase Iranian power and presence in Iraq. That, in turn, would precipitate a crisis between Iran and Saudi Arabia, two powers with substantial differences dividing them. The United States would then face the question of whether to support the Saudis against Iran. Placing forces in Saudi Arabia is the last thing the Americans or the Saudis want. But there is one thing that the Americans want less: Iranian dominance of the Arabian Peninsula.

Any president who simply withdrew forces from Iraq without a political settlement would find himself or herself in an enormously difficult position. Indeed, such a president would find himself or herself in a politically untenable position. The consequences of a withdrawal are as substantial as the consequences of remaining. The decline in violence and the emergence of some semblance of a political process tilts the politics of decision-making toward a phased withdrawal based on improvements on the ground and away from a phased withdrawal based on the premise that the situation on the ground will not improve. Therefore, even assuming Obama wins the nomination and the presidency, the likelihood of a rapid, unilateral withdrawal is minimal. The political cost of the consequences would be too high, and he wouldn’t be able to afford it.

Though Obama is the one outrider from the general consensus on Iraq, we would argue that the relative rhetorical consensus among the candidates extends to a practical consensus. It is not that presidents simply lie. It is that presidents frequently find themselves in situations where the things they want to do and the things they can do — and must do — diverge. We have written previously about situations in which policymakers are not really free to make policy. The consequences of policy choices constrain the policymaker. A president could choose a range of policies. But most have unacceptable outcomes, so geopolitical realities herd presidents in certain directions.
And in another article on Afghanistan Friedman concludes:

As the situation in Iraq settles down - and it appears to be doing so - more focus will be drawn to Afghanistan, the war that even opponents of Iraq have acknowledged as appropriate and important. But it is important to understand what this war consists of: It is a holding action against an enemy that cannot be defeated (absent greater force than is available) with open lines of supply into a country allied with the United States. It is a holding action waiting for certain knowledge of the status of al Qaeda, knowledge that likely will not come. Afghanistan is a war without exit and a war without victory. The politics are impenetrable, and it is even difficult to figure out whether allies like Pakistan are intending to help or are capable of helping.
Even if one doesn't agree with Friedman's assessment of the situation, the lack of coherent policy prescriptions from the candidates and, indeed, much of our political class is deeply disturbing to me. Lives literally are on the line and yet there is very little debate about what US interests are or should be much less discussion on how the political policy choices serve those interests. On top of all this it's clear, particularly with regard to Afghanistan, that many policymakers don't have even a decent layman's understanding of the history and complexities of these conflicts. It's all very frustrating....