Those countries with strong economy controls the world's political and religion system.
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.
To grow an economy is actually an intentionally direct step that doesn't happen by happenstance. A country that wants to be better economically and otherwise must make real steps to achieve that and gradually they get there. One factor to look at that makes a country great is the country's budget on education. education is key to development, if you lack education then different aspects of the economy will not develop like the technology and that is the most important that connects all other sectors of the economy. So most of the developed countries that have been mentioned have direct effort towards developing their educational system through budget yearly.
Most times,for some countries,going into debts is the only way it could raise funds to carry out various economical activities in her system.Meanwhile,debts is a tool and we're not allowed or supposed to feel comfortable been in debt.
Supposedly,any debt that did not yield or create the value its supposed to is a bad debt,when such a debt does not promote growth and elevate the economical activities in any way,it becomes difficult and unmanageable to the indebted country.In essence,such debt can lead to defeat and punishment.
Most people don't understand this,but no debt is a good debt or a bad debt,but the outcome from it is sincerely what makes it what it is.