The Borgist foreign policy of the administration has little to do with the generals.
To comprehend the generals one must understand their collective mentality and the process that raised them on high as a collective of their own. The post WW2 promotion process in the armed forces has produced a group at the top with a mentality that typically thinks rigorously but not imaginatively or creatively. These men got to their present ranks and positions by being conformist group thinkers who do not stray outside the "box" of their guidance from on high. They actually have scheduled conference calls among themselves to make sure everyone is "on board."
If asked at the top, where military command and political interaction intersect, what policy should be they always ask for more money and to be allowed to pursue outcomes that they can understand as victory and self fulfilling with regard to their collective self image as warrior chieftains.
In Obama's time they were asked what policy should be in Afghanistan and persuaded him to reinforce their dreams in Afghanistan no matter how unlikely it always was that a unified Western oriented nation could be made out of a collection of disparate mutually alien peoples.
In Trump's time his essential disinterest in foreign policy has led to a massive delegation of authority to Mattis and the leadership of the empire's forces. Their reaction to that is to look at their dimwitted guidance from on high (defeat IS, depose Assad and the SAG, triumph in Afghanistan) and to seek to impose their considerable available force to seek accomplishment as they see fit of this guidance in the absence of the kind of restrictions that Obama placed on them.
Like the brass, I, too, am a graduate of all those service schools that attend success from the Basic Course to the Army War College.
I will tell you again that the people at the top are not good at "the vision thing." They are not stupid at all but they are a collective of narrow thinkers. pl