Vast majority? Military spending is only 15.75% of the US federal budget. And that's just federal spending, citizens also pay taxes to states and municipalities, which rarely field combat aircraft.
From the BusinessInsider link below:
"The military budget is by far the largest single cost displayed. It is almost six times larger than the 2015 education budget and it is more than 34 times the size of NASA's 2015 operating budget. In total, the costs of running the military amount to approximately 16% of the overall 2015 US budget."
[1] http://www.businessinsider.com/the-us-defense-budget-is-mass...
[2] https://www.nationalpriorities.org/budget-basics/federal-bud...
http://www.huffingtonpost.com/2013/03/11/fukushima-navy-heal...
Even if you think that "Fighting ISIS" is destroying civilization (erm... ambiguous. They're destroying civilization. And we are destroying them. I'd say that's a net-gain), there are plenty of good-will projects from the military.
Like GPS, Nuclear Power, and more.
"Funding ISIS" (or loosely supplies and training for sectarian groups the US had(s) no control over).