Data: Foreign Debt as % of GDP

Understanding the debt burden is not as simple as it sounds because certain economies have lots of internal debt, especially if there are many transactions as there are in financially sophisticated economies. For example, to put it simply, if institution A owes institution B x amount, but institution A is also owed an identical amount by institution C, then A's debts can theoretically be considered as zero, but instead A's debts are counted in the total amount of debt. Such complications can make it difficult to get a clear grasp of the debt burden.

Although not foolproof, one of the best ways to measure the debt burden is to look at external or foreign debt. This is a measure of the total debt owed by government, institutions and people in a country to creditors outside that country. This measure tends to make bigger countries or economies - like the USA or Japan - look better than small countries because in large states those areas or sectors depending on debt are counterbalanced by areas and sectors supplying credit. This is one reason there are so many small European nations in the chart. The other reason is the sophistication of their economies and the past credit-worthiness that allowed them to borrow cheaply.

High external debt can hurt an economy, especially if confidence disappears, leading to a vicious cycle of increasingly expensive borrowing. This can lead to unsustainable debt and a collapse in the system. The World Bank and IMF believe that external public debt should be kept within 150% of a country's export earnings or 250 percent of a country's GDP.

Here is a list of the 20 countries with the highest foreign debt as % of GDP from 2011 (source CNBC):

1. Ireland 1,239% $2.26 trillion $478,987 per capita
2. UK 451% $10.157 trillion $161,110 per capita
3. Switzerland 391% $1.332 trillion $174,022 per capita
4. Netherlands 367% $2.590 trillion $154,820 per capita
5. Belgium 353% $1.457 trillion $139,613 per capita
6. Denmark 283% $591 billion $106,680 per capita
7. Hong Kong 266% $939 billion $131,380 per capita
8. Sweden 262% 995 billion $109,318 per capita
9. France 254% 5.632 trillion $85,824 per capita
10. Norway 246% 653 billion $138,783 per capita
11. Finland 245% 479 billion $90,984 per capita
12. Austria 241% 848 billion $103,160 per capita
13. Portugal 207% 511 billion $47,483 per capita
14. Germany 184% 5.674 trillion $69,788 per capita
15. Greece 178% 547 billion $50,792 per capita
16. Spain 169% 2.392 trillion $50,868 per capita
17. Australia 140% 1.283 trillion $58,322 per capita
18. Italy 137% 2.494 trillion $40,724 per capita
19. Hungary 110% 216 billion $21,706 per capita
20. USA 99% 14.959 trillion $47,664 per capita