With the fall of Mosul to the jihadists of Syria and Iraq, there is much blame-casting to be had. Some are blaming Obama for not keeping a residual force in Iraq although it is not clear that a small US force would have kept the Iraqi military from breaking.
Anyhow, this always, always frustrates me because it ignores what the US faced in 2009--the accumulation of dynamics produced by the bad decisions of the past. In this case, if people remember, there were many stories where Iraqi elites said two things: yes, we want the U.S. to stay, but no, we cannot say that in public. Why?
Pretty simple: occupation -> nationalism -> domestic politics -> no Status of Forces Agreement.
What does this mean? It might be easy to forget, but the US invaded Iraq and then occupied it for several years. That, by itself, would be enough to earn a heap of resentment and an anti-American nationalism. But then the occupation was so very badly implemented. The Coalition Provisional Authority was known as Can't Produce Anything. The US failed to prevent the looting that emerged after Hussein fell, it fired the entire Iraqi military, denied widows and orphans of their funding, fired most of the people associated with the Ba'athist party and thus deprived the government of pretty much everyone who needs to govern. Don't forget how Abu Ghraib presented endless pictures of the US humiliating Iraqis. I have not read many Iraq books since Fiasco, Cobra II, Assassin's Gate, and Imperial Life in an Emerald City, but the news stories since were not chockfull of happy stories about an improved US effort. Indeed, most refer to half-finished projects and heaps of collateral damage. I didn't even mention the private military contractors that used excessive force.
Anyway, the point is: the occupation did nothing but stir up resentment towards the U.S. While Iraqi nationalism is probably more complex than that, this one thread of Iraqi nationalism developed some saliency. So, then Iraq has a serious of elections and formal democracy, even if the system is flawed. Given the occupation, how can elected Iraqi leaders say in public: hey, those Americans that utterly humiliated us, but let's invite them to stick around? No, they obviously could not.
How can you expect Iraqi leaders be so brave and resist the public's desire to see the last of the Americans when American and other politicians are generally reluctant to buck the opinions of their base? Anyhow, so one could blame Obama for messing up the diplomacy of the negotiations of the SOFA if you want, but it is hard for me to imagine Iraqi politicians of that time frame signing off in public for more years of American soldiers in Iraq.
This is one of the ways that distinguishes Afghanistan from Iraq. Karzai has his own agenda and resists the demands of the rest of Afghan society. I guess he understands his base better than I do. But in Iraq, given how the occupation played it, the blame-casting today cannot start with Obama but with Bush, Cheney, Rumsfeld, Wolfowitz, Feith, Rice, and the rest. This is not my partisan animus showing here, but a basic understanding of path dependence (how early choices ultimately constrain decisions down the road) and of nationalism. As Bill Ayres and I argued in our book, nationalism frequently causes politicians to do stuff that is in the best interests of themselves but not in the best interests of the country--for kin, not country.
There are other questions now, like whether the US should launch air strikes to help the Iraq government and what it should/could get in exchange. But that is a post for another time.