On an article about tripwires and deterrence
Surveys at least begin to take seriously that nations aren't abstract entities who somehow immaculately act on self-interest or some other principle, but instead act through a series of institutional decisions, deliberations, policies, etc at different levels of the state, sometimes in contradictory ways. (As per How Reason Almost Lost Its Mind, etc.)
But to me the real test is what we can't see (and can't iterate, because official and civic actors aren't experimental test subjects), which is the in situ citation of various doctrines that are articulated in part to try and influence or direct state and interstate action--both the formal mention of something like "tripwire doctrine" or "MAD" in an actual conversation that is actually informing a contemplated or ongoing action or practice--and more folkloric discussion that is effectively synonymous with the formal idea even if the person speaking doesn't know about it. (e.g., sometimes we formalize an idea in scholarship that has been around in informal and folksonomic ways for a long time). It's not even enough to have transcripts or after-meeting documents or other kinds of writing that serve as evidence about what was said, because we've all been in meetings where the after-meeting archive somewhat fictionalizes what was said, or where the after-meeting archive excludes all the sidebar conversations and lunchtime whispers that were far more determinative, or where key participants spoke informally before the formal meeting and came to an understanding, or spoke informally after and essentially agreed to ignore what was said formally, etc. E.g, an ethnography of how decisions happen and how decisions inform (or don't inform) official action is what we need; it also what we will almost certainly never have.
I'd have to check the source, though I recall seeing this in a prior discussion and in figures presented at the Acquisition Research Symposium that for *U.S.* *operational* expenses, are actually lower for troops abroad than troops at home. So as a practical matter, bringing troops home doesn't save *DoD* money.
That said, I suspect this is true because of offsets by host countries plus sunk cost capital expenses, so more expensive in the big picture probably holds. It just is a meaningful caveat for U.S. budget battles.