America’s national debt has passed $40 trillion for the first time. That is such an enormous figure that it is difficult to comprehend. Divided across a US population of approximately 343 million, it amounts to around $117,000 of government debt for every man, woman and child.
The debt has accumulated over many years under both Republican and Democratic administrations. Successive governments have spent more than they have collected in taxes, borrowing to fund healthcare, Social Security, defence, emergency support and everyday government operations.
More recently, the cost of the war with Iran, tariff refunds and the tax cuts introduced in 2025 have added to the deficit. President Trump promised to restore fiscal discipline, but planned spending reductions have so far fallen short of expectations.
The immediate concern is not simply the size of the debt, but the cost of servicing it. As interest rates have risen, the US Government must pay substantially more interest to investors holding Treasury bonds. The Congressional Budget Office projects net interest costs of approximately $1 trillion in 2026, rising to more than $2 trillion by 2036. That’s over $5,800 per person per year – over $100 per week, just to service the debt.
Higher government borrowing can put upward pressure on bond yields, making mortgages and business loans more expensive. If investors became less confident in America’s finances, they could demand even higher returns for lending to the US Government. In an extreme scenario, confidence in the dollar’s position as the world’s leading reserve currency could also weaken.
However, this does not mean a crisis is imminent. America remains the world’s largest economy, the dollar is central to global trade, and US Treasury bonds operate within the world’s deepest and most liquid government bond market. Unlike an individual, a government does not have to repay all its debt at once; it can refinance maturing borrowing and has the ability to raise taxes.
For investors, the milestone is a reason for vigilance rather than panic. Persistent deficits may create periods of volatility in bonds, currencies and equity markets, but abandoning US investments altogether could mean missing opportunities in many of the world’s strongest companies.
The sensible response remains diversification: spreading investments across different countries, asset classes and currencies. America’s debt problem is significant, but it is one of many risks that a well-constructed long-term portfolio should be designed to withstand.
