I have to take issue with the now clichéd line that Afghanistan is harder than Iraq. It is hard - very hard - but saying it is "harder" is Monday morning quarterbacking with rose-colored glasses. As Iraq descended into chaos in 2004, 2005, 2006, and 2007, there was nothing "easy" about it. We forget that we spent years groping in the dark in Iraq with no real clue - on either side - about what to do.
The progressive argument for withdrawal did not really pick up steam until the fall of 2005. Prior to that progressives argued for more troops, a focus on nation-building, and protecting the population, (yes the very approaches that Petraeus implemented) but with little confidence it would work. Conservatives were wedded to a highly kinetic "kill bad guys" approach until they adopted what progressives had advocated in 04-05. The point being there was simply no straightforward approach to turn things around. The only thing that was clear was that the Administration's approach wasn't working.
By 06 and 07 the strategy began to shift and those running the war became more competent and pragmatic about U.S. goals and means. But the other factors that contributed to the decline in violence and greater stability were by no means a given or even foreseen. For instance, negotiations with former Sunni insurgents would not have been politically possible in the first few years of the war and there wasn't a real sense when they began that they would be successful. I never heard anyone say with confidence in 05-06 that the key was negotiating with insurgents. Once they began to show promise they were pursued vigorously. There were also inherent reductions in violence resulting from comprehensive ethnic cleansing, which were followed on by the efforts of U.S. forces to maintain the segregation of these neighborhoods. This contributed greatly to the let up in violence, but no one would have said that the ethnic cleansing or segregation of urban neighborhoods was easy. Finally, the gradual development of the Iraqi security forces and Iraqi capacity, which was by no means a given, enabled the U.S. to increasingly work with Iraqis and begin to transfer authority. U.S. strategy and policy played a key role in exploiting opportunities, but there was never any clear indication at the time that any of these efforts - negotiations, walling neighborhoods, and investing in Iraqi security forces, along with a counter-insurgency approach - would pay off.
Additionally, we spent a lot of money and threw the whole weight of the U.S. military behind these efforts - much more than we are imagining we will put into Afghanistan. And after all this and after being the sole focus of U.S. foreign policy and national security for five years, Iraq could easily still be pulled apart by ethno-sectarian violence.
Now - Afghanistan is hard, very hard. Its terrain is extremely challenging, its poor, the insurgency is rural-based, there is no history of a strong state, there are deep ethnic cleavages, it is bordered by an ungoverned region that serves as a safe haven and launching pad for attacks, and the insurgency is fueled by an uncontrollable drug trade. Oh it's bad, real bad. But Iraq had much of this as well, such as uncontrolled border with Syria that allowed insurgents to stream across, not to mention a meddling Iran. And Afghanistan has some advantages, baseline expectations are lower, we are still more popular, we have allies, and there is an Army that is respected.
The point though is that this debate over what is harder is really not all that helpful. Each pose exceptionally challenging and unique circumstances and shouldn't really be compared in such a direct way. It also raises the uncomfortable question: If we are truly committed to Afghanistan and believe that it is harder than Iraq, shouldn't we be committing more resources and manpower to Afghanistan than we did in Iraq?