Let me start off with an analogy here. Consider an individual who doesn’t have the means to go on a holiday to Europe but goes for one by taking a loan. But then he wants to send his children for education to good colleges. So he takes an education loan. And he also wants to buy a car. So he takes an auto loan. Loans becoming such a predominant part of his life that he starts using one set of loans to fund his other set.
Something similar has gone wrong with Uncle Sam. US has never stayed within its means. Whether manufacturing huge gas guzzling cars or spending trillions of dollars on mindless wars (Iraq and Afghanistan), the US govt. has always lived beyond its means. One would think that the crisis of 2008 which was the beginning of the economic collapse of the world would give them some sanity. But then as they say common sense is really not that common.