A 2004 article by Sherle R. Schwenninger discussed the possibility of us having a "Suez Moment."  He discusses that in 1956 France, Israel and Great Britain attempted to recapture the Suez Canal after its nationalization by Egypt.  Britain called off these effects not by a military defeat but by an economic one.  America refused to support the British pound, which created a monetary crisis for the British government.  Mr. Schwenninger warned, "As its international debt grows, the United States becomes ever more vulnerable to its own Suez moment." 

In late 2007 Chinese officials threatened such action.  A group of U.S. senators, backed by the Senate Finance Committee, drafted a bill that called for trade tariffs against Chinese goods as retaliation for alleged currency manipulation.  An article titled, "China threatens 'nuclear option' of dollar sales", noted, "Two officials at leading Communist Party bodies have given interviews in recent days warning - for the first time - that Beijing may use its $1.33 trillion of foreign reserves as a political weapon to counter pressure from the U.S. Congress." 

Foreign people and entities now own more than half of our Treasury bonds, amounting to more than $2 trillion.  I believe that this is a huge threat hanging over our economy.  Think of the problems that the recent decline in the value of our dollar is creating.