No nation has never defaulted on its debts. Throughout history, there have been instances of even the most economically stable nations defaulting on their debt obligations.

For example, the United States has defaulted on its debt obligations multiple times throughout its history, including during the Revolutionary War, the War of 1812, and the Civil War. However, due to its economic and political stability, the US has remained a strong borrower in the global financial markets and has been able to maintain its status as the world's reserve currency.

Similarly, other historically strong borrowers such as the United Kingdom, France, and Germany have also experienced periods of default throughout their history.

It's important to note that the concept of default can take many forms, from outright refusal to repay a debt to restructuring or renegotiating the terms of the debt. In some cases, nations may default on their debt obligations in a subtle or indirect way, such as through currency devaluation or inflation.

Overall, while some nations may have a better track record than others when it comes to debt repayment, it is difficult to make a definitive list of nations that have never defaulted on their debts, as almost every nation has experienced some form of default or restructuring throughout its history.