It's sinking for a number of reasons.
Federal defecit, low interest rates, credit crisis, CDO/CDS debt backed securities trend, real-estate bubble, oil prices.
Combine all of those issues which each in itself can become a problem if not managed properly and you have a really big problem.
Current Outlook: Stormy.
NO. Its sinking because the Military, namely the Pentagon, spend all of that money on "Star wars" like equipment, that costs trillions of dollars.
The stuff you sight would not have lead to the collapse of the dollar, rather it is the massive military spending, that Rumsfield did to transformed the Armed forces of the USA to the 21 century challenges.
This massive spending, is equal to all the world's military spending 400 times.
They tell you that the credit crisis is to blame but its not. its the military spending that broke the back of the economy.
Interestingly enough, that is how the Roman Empire collapsed, if you read history.