Same as Iraq.
Stay with it until you win.
Or, if you have a different point of view, leave the country to the enemy like the Democrats wanted us to in Iraq.
There is no such thing as an "exit strategy." It's a euphemism--giving up the fight wrapped in the pretty paper of some form of pretended success. Prior to Vietnam, any general in history you tried to explain it to would have thought you were nuts.
You either win and leave, lose and leave, or draw a line in the sand and stay there to guard it for years. This is how pretty much every war has ended.