How did US debt approach $40 trillion — and who pays for it?

The gross national debt of the United States officially reached $40 trillion for the first time in history this week, according to the US Treasury. This comes as the government continues to spend more than it earns, including on defence, Social Security and interest on the debt.

The latter alone now costs the government more than $1 trillion a year.

The milestone came as long-term US Treasury yields reached multi-year highs at the beginning of the week, reflecting investor concerns about inflation, global tensions and the country’s ballooning debt.

The more interest a country pays, the faster its debt grows.

The national debt has risen as the US borrows to cover repeated budget deficits. Higher interest costs add to spending, requiring further borrowing and risking a vicious cycle of rising debt.