OrOf course, we also went into both nations with a "this is not an occupation, and not going to be an occupation" position from the onset, so the military's guidance of 1:50 was never going to happen.
Which leads to the next set of problems, we didn't want to look like occupiers, so we drastically undermanned what needed to be sent. We also didn't want to look like "colonizers" or any stripe of "imperialist" so we were a "light touch" on a wide range of things. Meaning there was a broad array of things we should have acted on, but didn't, because we didn't want to make it easier for other nations (and people in our own) to accuse us of being imperialists(not that the approach worked in any case).
To continue this train a bit further, and to rehash some even earlier statements:
1) The United States should not attempt to "nation build" again unless they're willing to go "all in" (or can establish a coalition that can ensure they collectively do so). This means
the 1:50 ratio happens at the onset, and remains for a minimum of six, possibly longer depending on how quickly they establish civil authorities and/or other proxies to ensure that 1:50 ratio is maintained in some form. (soldier, police officer, or some kind of para-military force of local origin)
If you are unwilling to go for the 1:50 ratio, you aren't serious enough about it, and should recognize as much. And in light of what happened with the Northern Alliance in Afghanistan, and with the Iraqi defectors who were promising us the moon in early 2003... "Indigenous forces" are going to be completely and thoroughly vetted
to our standards before they are considered as part of the 1:50 ratio. (Exemption: recent hostile occupation -- see WW2 France)
2) If you're going to nation build, be ready and willing to completely own the "Imperial Colonialist" title. You're not going to avoid it in any case, and as demonstrated, seeking to avoid it doesn't make things better.
3) Do not tolerate corruption on the part of the local government officials who assume power while under our watch. Really, Vietnam should have taught us that much, seriously, WTF?
4) Prepare to be there for the long haul if it isn't a case of rescuing a recently invaded/occupied developed nation. It is going to be a generational undertaking, if you're unwilling to make plans for keeping a substantial number of troops
stationed there,
not to be confused with deployed for the next 20 years, don't send a large number of troops in there in the first place.
Of course, if we adhered to that Afghanistan wouldn't have cost us 2.2 Trillion over 20 years, it likely be a large multiple of it instead, but on the flip side, with a 50:1 ratio rather than what we did use, things would have likely been a lot more stable simply because they wouldn't have been able to do much. So expenses would have been wildly different(and both more and less effective in various ways--less corruption on their end, but some additional costs/resistance due to being openly and unapologetically occupied)... But it would have still been very expensive, far more so than what we did do.