"That would be nice if [people] stuck [treasury bills] all under a mattress, but they got to buy something with them. Sometimes they buy a treasury note, sometimes they set up sovereign wealth funds. They can do all kinds of things. They can buy our companies here. As long as we consume more than we produce, and we trade away little pieces of the country daily, they're going to own something. Now, they can't run from American assets. I mean every day the rest of the world is going to have about two billion more of American assets than we have, as long as they sell us these goods."

Source: Richard J. Connors, Warren Buffett (2010). “Warren Buffett on Business: Principles from the Sage of Omaha”, p.220, John Wiley & Sons