Which country has the strongest economy?

All the countries you mentioned would be near the bottom. Germany has the highest debt in the World, I doubt it would ever be able to pay it back, it was punishment for trying to invade other countries. As for the strongest most Asian Economies are in very good shape, although China is hotting up. If I was forced to choose it would be between Canada and Australia. The other Western economies will not be here in 20 years.