Insanity (noun): Doing the same thing over and over again expecting different results.Trump's speech tonight was a classic nothing burger. He didn't detail a plan, or outline a plan, or hint that there might even be a plan. There will be a troop surge. Just like in 2009 (multiple times), 2010 (to 100,000 soldiers), and 2015. Just like the Russians did during the 1980's.
This new surge that will have the same effect as the previous ones, Afghan fighters will melt into the population leaving few easy targets. Generals and politicians will become frustrated at the lack of any progress. There will be plenty of opium for bored soldiers to taste who will then be easy targets for hit-and-run attacks.
The one plan, such as it was, that Trump articulated was the promise of perpetual war. There was no stated goal except killing "terrorists." Where there is no goal there is no way of knowing if you've won. Winning becomes impossible.
For senior military officers a perpetual war allows for an endless collection of campaign ribbons, medals, and promotions. For weapons producers it means more decades of selling munitions to the army to be blown up and replaced by even more munitions.
And so the war will be passed to the next President, as it was passed from the previous two, and it will continue as long as there are patriotic young men willing to volunteer to be cannon fodder.