Trump strategy in Afghanistan

[Kagemusha]

i have some sympathy for trump here.

i am at heart a westphalian: where the compact of nations deems a state's territory and internal affairs to be inviolable, except whereby complicity or incompetence one permits attack upon other states from your own territory.

afghanistan is a failed state, which through a combination of both complicity and incompetence it allowed attacks on another state.
there are two options here:
1. intervene - to help build a real state capable of upholding its westphalian obligations to its neighbours. we have done this with some vigour, and at great cost in blood and treasure!
2. contain - after assessment that no escape from failed state is possible, simple wall the place in and use stand off munitions and special forces to smash anything that looks like a tall poppy.

the US has china to contend with and limited resources with which to do so, so I won't blame them if they decide that option 2 looks like the cheaper one for what is a sideshow and distraction from 'important' matters.

Im confused.Isnt Westphalia state in Germany?