COIN is viable and by virtually every metric, it worked in the timeframe we were around to implement it. I'm not following your criticism here. Iraq was not ready to stand on its own feet, that much I fully agree with, but the choice to leave was well, well above Petraeus' pay grade and ultimately rested with the Iraqi government. Even in hindsight, if I say "Here's Iraq in 2007, you have four years to do your best and then we're gone" COIN is still the only viable option unless you want to use the Russian method in Grozny.
Counterinsurgencies are incredibly difficult and messy, but to say its merely a set of tactics in absence of a larger strategy is disingenuous.
As a commanding general, you seek to win the war.
I can assure you sitting on a FOB and running daily patrols does jack shit in terms of winning anything whatsoever, much less the overall war. How do you measure "winning" the Iraq war, which was a classic insurgency? By what metric is "success" being judged? Body counts mean nothing, caches discovered mean nothing, HVTs means nothing. There's no opposing standing army, no front line to move, no territory to gain, no regime to remove and we had full air superiority. So by what measurement are you judging success of a commanding general in Iraq?
If you are only instituting a delaying strategy that has only temporary (Iraq) success or little success (Afghanistan), you aren't a successful general.
This is a strong area where we disagree. Dismissing COIN in Iraq as a mere "delaying" strategy is, in my opinion, misguided. Petraues inherited a pile of shit in Iraq, I don't think anyone would deny that, and what his staff was able to accomplish in short order was an absolute improvement. Iraq didn't fall apart until A) Syria broke out into a civil war and B) al-Maliki's government refused the immunity clause in the SAFA (which resulted in us leaving.) Neither of those had anything to do with Petraues and while I'm personally inclined to believe that the Obama administration didn't push too hard on the SAFA, it was ultimately up to Iraq.
For example, COIN would not work in Afghanistan without addressing the corrupt Karzai government, the ineptitude of the Afghan military and police force, and most importantly, dealing with the Taliban sanctuaries and support in Pakistan.
I agree with this, but again, Afghanistan is also a different beast. I'm far more bearish on Afghanistan in general given how rural it is, the minimal population density, limited resources worthy of foreign investment, landlocked, etc. Essentially, I have zero hope for Afghanistan unless you drop a half million troops there, seal the Pakistan border (not going to happen) and spend 20 years educating/developing. And even then I'm still extremely doubtful.
As shitty as Karzai is, he's ultimately the sovereign leader of Afghanistan. The commanding general of ISAF can't just sack him in the middle of the night and install some random Kabul resident he likes.
I'm not saying COIN is the be-all end-all method of warfare, but I absolutely reject the idea that it didn't work in Iraq and was more of a temporary band-aid than anything. Afghanistan... well it's fucked regardless.
That doesn't erase the onus of responsibility of the commanding general to institute a strategy that will be successful. Merely buying time by buying off 100,000 Sunnis and ignoring the deep divide between the Sunnis, Shiites, and Kurds did nothing to address the deeper societal issues that COIN claims to address.
In four years, you're not going to fix those societal issues. Period. And you're especially not going to when the previous ~3 years have been spent fucking everything up through a disastrous civil-military occupation "strategy" (using that word hurts in this context.)
COIN in Iraq was far more than just "buying off" the Sunnis via SOI. That was one component that had actually started on a small scale before Petraeus took over command of MNF-I.