Unfair share? Based on what? The spending is directly correlated to USA's interests, there is no nanny-ing or "good will" going on, it's a matter of purely international interests. Looking at this with the patronising "unfair share" is a bit preposterous.
I'd say it's pretty unfair to a lot of countries being forced under the sphere of influence of the US to be continuously subjugated, through foreign policy or direct meddling in internal affairs, like the whole of Latin America. That is really fucking unfair.
Do you really believe the US has been doing that selflessly?
I mean, it's OK to no longer want to be an imperialistic nation. The feeling I get from people with that kind of message, though, is that they usually don't want to lose the benefits of being hegemonic. They just don't want to pay the upkeep for it.
A loss of military hegemony will most likely reduce the US's global political and economic role as other countries move to fill that void or take advantage of the absence (China, Russia, at present). The net effect will likely be a shrinking of the US economy in the end, and not growth or even sustainment.
With respect to the substance of your comment, sure, Trump talked a good game about stopping the stupid wars. He just never got around to actually doing that.