They’ve also ran a few state-level scams and Ponzi schemes to have the funds for that military and other spending.
Their business model was - step 1, cheat to have money, step 2, use money to rearm, step 3, conquer and loot, thus get funds that way, step 4 probably would be to force some peace, then rearm, then rinse and repeat, but they didn’t manage to capture a few strategic areas they needed in time. So they had fuel shortages, food shortages, and ultimately lost.