It could also be that the tide is changing and we did have the security ROI until cheap drone tech emerged to push us to a new gen of warfare.

For example, there is still a stable petrodollar, there are 11 carrier battle groups and 70 nuclear subs out there, there is an experienced US military capable of force projection. These are a few random metrics from a casual observer, and we seem to get more out of spending than some rival countries.