The Greek debt crisis poses a major obstacle for the world economy to overcome before global markets can begin to rally. Greece's GDP currently stands at 240 billion euros, but the financially weak European country will have to pay as much as 53.2 billion euros for its matured debts later this year. The possible insolvency of Greece has raised concerns among countries worldwide, causing them to live within their means. Tao Dong, Chief Economist of the Asia-Pacific regions for Credit Suisse First Boston, warned of a sovereign debt crisis against the backdrop of rampant government spending in many countries in Capital Week magazine. Edited excerpts follow:

In the past 18 months, governments across the globe have shared in one particular financial practice—they have all tried to spend as much money as possible to stimulate their economies. But in the next decade, they will be forced to embark on another journey: paying back their debts. Spending those vast sums of money was no easy task in terms of prioritizing projects, but paying off the debts will prove to be even more difficult.

The sovereign debt problem will linger and plague the market, possibly causing renewed financial turmoil at any time.

The Greek debt crisis ushered in a new era in modern capitalism and with it the reality that the sovereign credit of a developed country is not always reliable. Greece's national treasury securities are not being sold as quickly as before, as investors become concerned with the mounting risks associated with the securities.

The financial crisis and the ensuing credit tightening in the wake of the economic recovery have exposed the deep-rooted problems in the past 10 years of economic development. The problem in Greece is only the tip of the iceberg. The financial deficits of PIGS (Portugal, Ireland, Greece and Spain) account for 9.3 percent, 11.4 percent, 12.5 percent and 11.4 percent of their national GDP, respectively, three or four times higher than the standard proportion stated by the IMF. The high level of financial deficits, coupled with huge trade deficits, are rare in developed countries, and the involved countries should be put onto a "high risk" list.

All in all, the scale of Greece's debt is not substantial enough to crash the whole country, as a helping hand from the EU or the IMF would be enough to pull it out of its current predicament. But if a larger country is faced with debt pressures, the EU and euro might be in serious trouble.

The next game could be played with British or French finances, or even the United States. To save the banks from bankruptcy and stimulate economic development, the French financial deficit stands as high as 8 percent of its GDP, while the case in Britain is worse—12.6 percent. The U.S. budget deficit in 2010 is projected at 9.9 percent of GDP.

The high proportion means they will be forced to sell more treasury securities to fund the operation of their programs, leading to low yields of those securities, which will be ditched by investors due to low profitability.

The monetary expansion and excess liquidity pumped into the market has already made the central banks short on ways in dealing with the situation, forcing them to tighten controls over loose credit. But how to dispose of all the securities they sold during the crisis period remains a challenge.

The next hidden global crisis, therefore, might start with the treasury securities of major economies, leading to another downturn if left unchecked.