This is not a trick question or a gimmick.
Let us suppose that President Barack Obama, the Commander-in-Chief, appointed you to be his National Security Advisor, and wanted your serious advice on future policy in Afghanistan and any related areas.
Let us also suppose that his confidence in you was so strong, that your opinions and recommendations would prevail, and the Secretaries of State and Defense would follow your lead.
Let us further suppose that the President assured you that he fully trusted your judgment and would see to it that your plans would be carried out to the best of his authority and ability.
(Now don't be offended because I called you an arm-chair strategist. Almost all of us are exactly that. Certainly the National Security Advisor is. Certainly the President is. And there is nothing wrong with that; it is just the way things are.)
Let us assume that you take this responsibility as seriously as you can. You have been following the war for the past 10 years, but you are going to brush up on the real facts before you start making proposals that will be quickly turned into operational plans and orders. You can get your information from anywhere, but if you'd like just a bit of quick input, you could check with Fred Reed for a pretty up-to-date view.
Of course, having plenary authority, you have plenary responsibility for the outcome.
Basically, what would you actually propose -- all things considered? Precisely all things, considered.
You may consider the comments section as a great place to develop your assumptions, your objectives, and your means and methods. And, you will probably get at least as good feedback as the real National Security Advisor.