Why is America Intentionally Throwing Away its Global Power?

Only $4 Trillion of the national debt is held by official accounts for foreign governments - which is simply the scaffolding for trade. The remainder of foreign holdings, as well as a significant portion of mutual fund holdings and direct bond holdings are held by the wealthy and very wealthy. The top 1% holds approximately half of that class of debt, with the top 0.1% holding most of that. On the whole, after taking out official accounts held by the federal government, state governments and foreign governments - but not including social security, the debt held for households and the rich is under $30T, with half of that held by the rich and the other half held in retirement and pension accounts and the social security trust fund. 

High interest debt - $15T - would go to better instruments - such as the Euro - if the Euro were backed by dedicated revenue streams rather than central bank operations - but because the Euro is not backed in that manner, this portion of the national debt is what backstops speculation in the financial markets. The reason it is held is because such markets tend to fall. When they do, the rich can fall back on their debt holdings. Unless the very wealthy want to bring down the whole system, the debt is a safe bet.