The U.S. national debt has reached a historical high, with 25% of tax revenue being used to pay interest, which indeed raises concerns about inflation, long-term fiscal stability, and the future direction of the dollar. The specifics are as follows:

Inflation Aspect

- Increase in Money Supply: To repay debt and pay interest, the U.S. government may adopt the method of issuing more currency, which will increase the money supply and thus trigger inflation.

- Demand-Pull Inflation: By borrowing to maintain fiscal spending, the government may stimulate economic growth and increase total demand. If supply cannot respond quickly, it may lead to rising prices and trigger demand-pull inflation.