American military spending is only possible because the dollar is the reserve currency. This is not an opinion. It is arithmetic. The United States runs persistent deficits that would be unsustainable for any other country. It finances those deficits by issuing Treasury bonds. Foreign central banks buy those bonds because they need dollar-denominated assets for their reserves. They need dollar-denominated reserves because the dollar is the currency of global trade. The circle is closed. Military spending → deficit → Treasury bonds → foreign purchase → dollar demand → reserve currency status → military spending. Break any link in that chain and the whole logic shifts. This is why dedollarization is not just an economic story. It is the foundational strategic threat to American military primacy. Not Russian missiles. Not Chinese carriers. Foreign central banks deciding to hold a more diversified reserve portfolio. The most important battlefield of this century looks like a spreadsheet. The side that understands this is already fighting.