This whole question of financing war, as it is done nowadays, is not fully understood. In bygone days it had to be done by inflating the currency, and before that by hoarding up treasure or hoarding up actual gold 'value of one sort or another.
"Finance in War,"
Naval War College Review: Vol. 2
, Article 3.
Available at: https://digital-commons.usnwc.edu/nwc-review/vol2/iss6/3