If you have been in the military, you could possibly comprehend why this would not work. Your plan is not feasible. 500 linguists? That are qualified and properly trained? Yes, DLI can facilitate that. American Divisions of Dari and Pashtun speaking troops? Can never happen. We already have those troops anyway...they are known as the ANA.
I'm thinking about it on a different time scale. Maybe we need to just send more troops now and have a radically broader language training program up and running in 2 years or something. IMO we're not getting out of either war with a clear conscience in less than 5 years... Even then, only if we radically ramp up reconstruction.
I definitely appreciate your perspective. I was against the Iraq war from the start and had serious concerns about the scope of the Afganistan war from the start for pretty much the same reasons you're citing- the tasks of securing a country, replacing governments, rebuilding and establishing a working country are monumental. Maybe even impossible. But what irritates me is that the same folks who were ignoring those arguments when things were getting ramped up are now making those arguments themselves. IMO once you start a war you have an absolute responsibility to see it through not just to a military victory, but to a situation that is better than what was there before you started the war. People living there need to look back at the war and think "that was awful, but on balance I'm glad it happened". To start up a war then cut and run before you reach that point is indefensible. Best not to start the war, but once you do, you need to be in for the long haul. It sucks, I would never have wished this on the US, but we brought it on ourselves.
What I would do in both Iraq and Afganistan would be to add on two objectives- reconstruction and winning the hearts and minds. We give both of those lip service, but no real steps towards achieving them. To really reconstruct the countries means hundreds of billions of dollars in construction projects. Winning the hearts and minds means at the very least tens of thousands of Americans on the ground, speaking the language, and getting to know the people in positive ways. Those are massive goals, but that's what we bit off when we launched these ill advised wars.
I would like to see a massive reconstruction corp set up on the scale of the peace corp, bring in tens of thousands of non-combatants with experience in things like construction, city planning, economics, finance, computers, etc, have them work on major substantive projects to rebuild the countries, hire loads of Iraqis and Afgans to work on the projects, and make sure that all the Americans on the projects are speaking the language and working side by side with the locals. There really is no short cut to getting the population of the world there to realize that we aren't devils. You just need to provide them individually with exposure to Americans that speak their language and are engaged in some kind of positive, constructive, work that makes their lives better. That's the only way to really win hearts and minds. The people working in something like that would be taking serious risks to their lives to be sure so I would extend them veteran's benefits. I would use a significant portion of the increased troop numbers to try to keep those projects as secure as possible.
It'd be a long expensive road, but the alternatives are either to cut and run, in which case all we've done is screw up two countries and create tens of thousands of new terrorists, or to stick around with our limited scope mission for decades until the countries are able to rebuild the damage we did on their own. I'd rather sink more money in and get it over with quicker.