In other for a country to grow in all area's, it's major focus should be growing her economy, when this is achieved then that nation will become one of the most powerful nations in the world.
United States, China, Russia and Germany. This aforementioned nation's are seen as the most powerful nations of the world they all have a strong economy, strong economy is the beginning of a powerful nation.
Do you think that top nations will allow the country that they don't want to rise, to rise? For example, Germany wouldn't be so powerful if it wasn't the USA and their strategy to invest in Germany instead of destroying it (Germany's luck is that it's the center of Europe and it also reached an agreement with the USA to send a very high qualified scientists to the USA in exchange of money).
Check this
https://en.wikipedia.org/wiki/List_of_countries_by_external_debtUnited states is number one, China is number ten, Russia is number twenty nine, and Germany is number eight. It means you're wrong if you think strong economy countries aren't in debt.
Debt isn't always bad for filthy rich people or countries, watch Robert Kiyosaki how he use debt to make more money and protect his wealth.
I think he means that strong countries give debt to poor countries and that's true. When country takes a loan, it will take a loan in the USD and Euro instead of Indian rupee because these two currencies are the most stable and traded ones compared to others. The USA and EU can easily print USD and Euro and still they'll be demanded by every country in the world while poor countries can't do that or their local currency will devalue.