Bangladesh, Aug. 22 -- The United States has crossed a financial threshold that should command far more attention than it has received: its national debt has surpassed $40 trillion. The number is so enormous that it is difficult to comprehend. Yet behind the staggering figure lies a much more consequential reality-Washington is borrowing at a pace that is increasingly difficult to reconcile with long-term fiscal stability.

The milestone was reached months earlier than previously expected, underscoring how quickly the US governments liabilities are expanding. Treasury Department figures released on August 19 showed total outstanding federal debt at approximately $40.05 trillion. Since March alone, the debt has increased by about $1 trilli...