Is the real reason we are still engaged in Afghanastan after 16 years, the fact that Pakistan is a nuclear power? Should Pakistan’s government fall to the extremists we would have a nuclear armed Taliban, and all our worst fears will have become reality. Also, Pakistan, who has taken many losses in their stuggle with the Taliban, barely controls much of the border lands that it shares with Afghanistan. If the United States were to exit, China would surely rush in to fill the vacum. Pakistan has nuclear armed India to contend with also. In the Kasmir, the two sides are nose to nose. Often trading shots and moments away from escaslasting into a full hot shooting border war.,
I agree that this is what made the Trtump decision to abandon the TPP such an agregious move. So obsessed with reversing anything President Obama did, not only with the TPP but also the Paris Accords on climate change. Both these actions gave China a tremendous economic opportunity.
This is why I see no exit for the American military from Afghanistan any time in the forseeable future. The answers are the Taliban, and China.