When people worldwide are anxiously looking on as the eurozone debt crisis deepens, America, also mired in mountains of public debt, poses another potential threat to the global financial system.

Debt's siren call has already been sounded in the world's largest economy. By the end of last year, the U.S. public debt-to-GDP ratio was almost 70 percent, comparable to that of Spain, which was currently teetering on the brink of a dangerous debt crash.

Moreover, despite the Obama administration's efforts to jumpstart the sluggish economy and create more private-sector jobs, the U.S. economic recovery has been stalled over the past few months and the revival of the bleak job market has also been weakened.

Attempting to stimulate the U.S. economy, the U.S. Federal Reserve extended on Wednesday its so-called Operation Twist program to the year's end through selling short-term securities and acquiring long-term ones to encourage borrowing and spending.

In fact, the newly-announced 267-billion-U.S.-dollar extension, or the previous two rounds of Quantitative Easing (QE), are, by nature, designed to boost growth by flooding the U.S. economy with large quantities of dollars.

Additionally, the Federal Reserve has been sticking to a policy of super low interest rates ever since late 2008. According to its latest statement, the U.S. central bank will keep its benchmark refinancing interest rates as low as zero to 0.25 percent until at least late 2014.

No matter what the Federal Reserve might call them, those moves, as many have complained, amount to a policy of printing money out of thin air.

The problem is that the U.S. dollar, as a dominant currency in the global economic and financial systems, has a much bigger impact on the world than any other sovereign currency.

Many around the world shudders at the mere thought of the dire consequences that might be brought about by these historic liquidity-injection moves of the U.S. central bank.

Excessive dollar liquidity in the world, from a long perspective, will drive up commodities prices eventually, lead to disorderly cross-border flows of speculative funds, raise inflation, and devaluate the huge dollar assets held by countries like China.

A number of countries, notably Russia, have expressed their strong reservations towards the ultra-easing monetary policy in America.

For America itself, the effect of printing money on the real economy is also dubious. In the past few years, the Federal Reserve has already poured massive amounts of cheap dollars into its financial system, yet the U.S. economy is still struggling.

As many have suggested, money-printing cannot pull America out of its economic and financial quagmire.

To cure its problems, the United States should, among many other things, control its runaway fiscal deficits by cutting its gigantic military spending and bloated entitlement programs. It should also rein in the oversized financial sector and revitalize the "real economy."