Most arguments about dollar dominance focus on reserve holdings and Treasury demand. There is a deeper layer: the Fed's swap line network. When dollar funding seizes in a crisis, foreign central banks cannot print dollars. They can draw down reserves, but reserves run out. What they can do is call the Fed. The Fed creates dollars on demand and swaps them temporarily for the requesting central bank's local currency. No other institution can do this at global scale. The euro, yen, and yuan have no equivalent backstop. This means the US is not just the issuer of the world's preferred reserve currency. It is the lender of last resort for the entire global dollar system. In 2020, when dollar funding markets seized, the Fed activated swap lines with 14 central banks. Markets stabilized almost immediately. Not because traders suddenly trusted America more, but because there was only one institution capable of supplying dollars without limit. If a country or bloc wanted to meaningfully reduce dollar dependence, they would not just need an alternative reserve asset. They would need an alternative emergency dollar supplier. What would that even look like?