What you're missing here is that the whole idea of recruiting locals directly into the armed forces of a foreign power is only possible is the foreign power rules the area. You can't do it if there's an even nominally sovereign local government in the picture. The US could and did form such units in its colony in the Philippines. It couldn't and didn't and hasn't in Vietnam, Iraq, or Afghanistan because these are not direct imperial ventures where the US is setting up to rule, they are nominally sovereign states with their own governments and armed forces.

Either you're a colonial power, in which case you can and will take direct control of indigenous armed forces, or you're not, in which case you can't and won't. Can't have it both ways.
Exactly, that is why trying to compare the U.S. foreign capacity building to European foreign conscripts lead by Europeans is futile exercise. If we integrated foreign troops into our logistic, C2, medical, fires and intelligence systems and led them with U.S. officers and senior NCOs we could rapidly employ relatively effective forces that were largely composed of foreign troops. However, in a FID scenario that just isn't possible.

Other comments were not accurate either. Our political patience is rarely the problem. It doesn't take 10 plus years to develop a relatively effective fighting force. It may or may not take 10 plus years to stomp out an insurgency, but that is a different issue.

Where I think we go wrong (and this is just a start):

- We try to develop forces that mirror the U.S. force structure and tell them to employ our doctrine. It is generally too sosphisticated for most in developing nations to replicate, culturally inappropriate, and fiscally unsustainable.

- Department of State has responsibility for security assistance and frankly they don't know what they're doing. They have a long track record of throwing millions of dollars at these challenges with little understanding of what is actually required. The worst part is they do not develop a logistics system for the supported nation that is sustainable (if they develop one at all). If Americans had a better appreciation of how much Dept of State spent on these efforts and what little they have to show for it, I suspect more authorities would shift back to the military. State should own policy and have a veto vote, but once a decision is made to execute they need to enable and stop impeding.

- If it is a security assistance Mobile Training Team U.S. forces do not have the authority to combat advise, only to train and equip. Without mentoring them in combat it is very difficult for those trained to transition from the classroom and range to the battlefield. Mentors in the field instill confidence and can make on the spot corrections and identify shortfalls in training that need to be addressed. As that military matures over time these lessons are incorporated in their doctrine (not U.S. doctrine with their country's name stamped over it) and taught in their schools.

- Not surprisingly, when forces that are actually trained to build partner security forces like U.S. Special Forces have the resources and authorities to do so like they did in Iraq and Afghanistan they developed some very capable partner Special Forces units. Much better than the sepoys and numerous other forces developed by the Europeans during the colonial years. The point is the U.S. can do this if we have the right people in charge it enabled with the right authorities and resources. We have a proven track record. We have a dysfunctional bureaucracy and disparate authorities that make effective execution difficult at best, impossible at worst.