How would a BTC country defend itself?

(No utopian answers please: war is unfortunately something our species loves and lives to do)

A country not on a hard money standard raises money for war by issuing debt. This was done even during the gold standard days, causing intentional currency devaluation. This causes inflation, of course, but also leads to availability of resources for defence spending.

If 2 countries collided, one with a BTC economy, and the other completely fiat, how would the BTC economy counter the aggressor?