Greenspan talks, he didn't saw the previous crisis coming, so don't expect he will be right this time. The bond markets can collapse, but not together with the stock markets.. money has to go somewhere. If trust in governments declines, the trust in the private market increases. This is what is happening at the moment, but the collapse of the bond market hasn't happenes yet because the central bankers are buying bonds. The question Greenspan should be asking is: who else is willing to buy them? Governments have a tendency to default on their debt.