How, and When, do resource constraints affect Just Cause 2?

I found the exact same thing. The only thing I could surmise is that it is a way of increasing the difficulty curve.

There is probably some rubbish justification for it along the lines of "the Panauan military is taking measures to stop you from destabilising their country" or some rubbish. Dunno why they wouldn't just put a bullet in your head and go back to dictatoring...

As for the resource constraints, I'm not overly convinced that they affect anything. Having completed the game, nothing really seemed to change much, other than the aforementioned increase in difficulty when getting 100% on settlements.