[U.S. National Debt Reaches $39 Trillion, Sparking Long-Term Concerns; Analysis Indicates Rising Risk of Unsustainable Fiscal Path] BlockBeats News, July 5: The U.S. national debt has risen to approximately $39 trillion, with public debt now equivalent to the total U.S. GDP. Annual interest payments have reached about $1 trillion, surpassing the defense budget. The U.S. national debt system can be traced back to 1790, when Alexander Hamilton initiated debt consolidation reforms. At that time, the federal government assumed the wartime debts of individual states and committed to full repayment, thereby establishing the U.S. credit system and laying the foundation for the global status of the U.S. dollar and U.S. Treasury bonds. Today, U.S. Treasury bonds are regarded as one of the core assets of the global financial system, supporting the reserve currency status of the United States dollar and widely held by global central banks and financial institutions. However, as the debt level continues to expand, concerns about long-term sustainability are intensifying. According to the Penn Wharton Budget Model (PWBM), when the debt-to-GDP ratio exceeds approximately 210%, the fiscal system may face unsustainable risks. Currently, this ratio in the U.S. is around 100%, and the Congressional Budget Office projects it could rise to 175% by 2056. Analysts believe that under scenarios of increasing healthcare expenditures and persistent fiscal deficits, this risk threshold could be reached earlier. The long-term stability of the debt structure is facing stricter scrutiny from both markets and policymakers. [Original Link]