Derivatives could set off a global chain reaction. Most people have heard of the complex, “synthetic” financial securities known as derivatives, which Warren Buffett famously referred to as “financial weapons of mass destruction.” In the case of bonds, these are known as credit derivatives. They include all sorts of loans secured by bonds, as well as incredibly complicated vehicles that amount to insurance policies if the bonds default. No one really knows how much of this stuff is sloshing around the international financial system, but the total value for all types of bonds was estimated at more than $50 trillion in 2008 and has continued to grow rapidly since then. Trouble is, if the bonds underlying these derivatives become questionable, all the derivatives become uncertain, too, even if they add up to far more than the value of the bonds themselves. Moreover, some of the synthetic investments based on Greek bonds could be governed by Greek law, some by British law (if anything originated in London), and some by U.S. law (if Wall Street was involved).

What if one legal system accepts the conversion of euro loans into drachmas and another one doesn’t? Everything could be thrown into the courts for months. Even worse, if synthetic investments secured by Greek bonds become untrustworthy, why would anyone trust similarly complex investments involving Spanish bonds or Italian bonds?

The result of a meltdown in the world of derivative investments could cause far more chaos than simple bond defaults, not least because it would be almost impossible to figure out who owed how much to whom.