Fred: Obama will say any pin-headed thing he feels like on foreign affairs, so long as it doesn't require him to actually follow through with any of it. I'm not president or running for president; if I say "invade Pakistan!", it'd just be some fool saying something stupid on the internet. Obama, on the other hand, had somebody mis-brief him & blurted out, stupidly, some idiocy about invading a nominal allied state during the campaign season.
The reason that Pakistan is such a hellacious problem is that they're nominally our allies. (Same with the Saudis, but the Royal Family isn't a nuclear power. Yet.) Without causus belli, we can't out-right invade the technically sovereign state of Pakistan. The CIA crawls all over that county with the half-hearted connivance of the Pakistanis - there was one heck of a wild-west show in the Kyber Agency recently. We conduct quiet cross-border attacks all the time. But I *don't* think we should declare open war on the Frontier Agencies. It's not the delicate or nuanced way to go about things.
But more importantly, Afghanistan isn't a cultural or political priority. Afghanistan is a proxy to a proxy, at least two removes from the strategic pivot. All we can do in Afghanistan is kill jihadis. More importantly, we can *lose* in Afghanistan, but we can't win there. It's an attritional fight, and the modern United States isn't a power which can win on attritional terms. It only works if we change our terms, our definitions. Afghanistan is far enough out of the Islamic heartland that it'll never register as anything other than "an affair of posts". You can win hearts and minds locally in Afghanistan proper, but what you do in that country won't swing the Islamic public regionally or internationally one way or the other.
Iraq is the emotional heartland of the modern Islamic world, or at least as close as we can get without waging war on a nominal sovereign allied state. And last year the Salafis wrecked themselves in front of the Muslim world, right in the heart of the old caliphate. They butchered and they slaughtered and they demonstrated their ideals before the cameras.
Iraq was where we could show the Islamic world a choice of definitions: does "Muslim" mean takfirism, salafism? Or are the Takfiri devil-worshipers, nihilistic, solipistic, savages, criminals - safely *not Muslim*?
I'm sanguine about Iraq because it looks like Iraq broke the Sunni regional threat. Since last summer, it's been a worry about whether there would be a count-rout and regional civil war between the resurgent Shia trends - the "Shia Crescent" - and a beaten Sunni cultural trend. The unexpected "Iranian subversion" mini-civil war seems to have put paid to the threat of the "Shia Crescent", though.
On a related note, I'm having difficulty figuring out what the heck happened last month in Basra and Sadr City, but there are a couple of alternate interpretations.
1) The various Iranian-suborned groups in the Iraqi Shia community had a falling-out-between-thieves, and the Iranians tried to salvage the situation by throwing the Sadrists to the wolves.
2) al Maliki had a sudden surge of patriotic feeling, and decided to assert national control over Basra.
3) Sadr failed to impress anyone in Teheran with his ability to mobilize the masses, and the fighting was *started* by Iranian intervention, against Sadr.
4) al Maliki and SIIC finally gave in to American badgering, and decided to reconcile with the Sunni Awakening folks by waging their own little demonstrative war-against-terrrorists-and-takfiri. Sadr, being the least politically apt and by far the youngest and dumbest of Shia powerbrokers, got chosen as the judas goat for this demonstration. The governmental Shia factions, having fought and won a much more conventional war against their own head-choppers and lunatics, are now exploiting an opportunity to meet on common terms with the newly-sympathetic Sunni Awakening community leaders.
I like #4 much more than the other explanations of what's going on. It explains what happened to the abortive "Shia Awakening" movement from last winter. If the Shias in government let that go on for too long, they would have failed to protect their phoney-baloney jobs. In order to avoid another bottom-up counter-insurgency, they and the Iranians are colluding to make the pacification of the south a top-down national project. It *sounds* like the Iranians may have out-maneuvered themselves, though. And there was always a chance that the Iranians would shoot themselves in the foot like this. Whenever you try to buy everybody in a factional snake-pit, you end up buying nobody; because all the factions are bought off equally, none of them feel beholden for the money and support delivered. Aid becomes tribute when it is expected, and leverage depends upon uncertainty.