Unlike past crises like 2008, the coming debt sustainability crisis will be different because the government's own balance sheet is the source of the instability. This means it will lack the capacity to bail out the market in the same way, fundamentally changing the nature of the crisis.
When national debt grows too large, an economy enters "fiscal dominance." The central bank loses its ability to manage the economy, as raising rates causes hyperinflation to cover debt payments while lowering them creates massive asset bubbles, leaving no good options.
Unlike the post-GFC era, governments now lack the fiscal and monetary flexibility to cushion every economic shock due to high debt levels. This is forcing global markets to trade on their own fundamentals again, creating volatility and relative value opportunities reminiscent of the pre-2008 era.
The US is not facing a single issue but a convergence of multiple stressors. Unsustainable fiscal policy, fragile funding markets, geopolitical shifts, energy production issues, and leveraged financial players create a highly volatile environment where one failure could trigger a cascade.
Despite recent concerns about private credit quality, the most rapid and substantial growth in debt since the GFC has occurred in the government sector. This makes the government bond market, not private credit, the most likely source of a future systemic crisis, especially in a rising rate environment.
Global governments are actively pursuing policies (running economies hot, suppressing energy costs, managing rates down) to create a period of artificial prosperity. This is a deliberate strategy to push a massive debt sustainability crisis further into the future, which will feel great until it doesn't.
Governments with massive debt cannot afford to keep interest rates high, as refinancing becomes prohibitively expensive. This forces central banks to lower rates and print money, even when it fuels asset bubbles. The only exits are an unprecedented productivity boom (like from AI) or a devastating economic collapse.
When a government's deficit spending forces it to borrow new money simply to cover the interest on existing debt, it enters a self-perpetuating "debt death spiral." This weakens the nation's financial position until it either defaults or is forced to make brutal, unpopular cuts, risking internal turmoil.
The underlying math of U.S. debt is unsustainable, but the system holds together on pure confidence. The final collapse won't be a slow leak but a sudden 'pop'—an overnight freeze when investors collectively stop believing the government can honor its debts, a point which cannot be timed.
For 40 years, falling rates pushed 'safe' bond funds into increasingly risky assets to chase yield. With rates now rising, these mis-categorized portfolios are the most vulnerable part of the financial system. A crisis in credit or sovereign debt is more probable than a stock-market-led crash.
The U.S. government's debt is so large that the Federal Reserve is trapped. Raising interest rates would trigger a government default, while cutting them would further inflate the 'everything bubble.' Either path leads to a systemic crisis, a situation economists call 'fiscal dominance.'