To be prepared for war is one of the most effectual means of preserving peace.

Readiness changes what other people attempt. When you are visibly able to withstand a thing, the thing is less often tried, and the strength ends up never being used, which makes it look unnecessary in hindsight. That is the paradox of preparation: it works by not being needed, so it is always the first thing cut.

Look at where you are exposed: money with no margin, a job with no alternative, a situation where you could not afford to say no. Build a little slack into one of those places. The purpose is not confrontation but never being forced into a bad answer.