The lack of preparedness around the world poses the biggest threat to the stability of the financial markets. Notice that Brazil is on the list. A couple of months ago, the head of Brazil's central bank resigned and their currency, the real, collapsed. The result was a shockwave that hit stock markets around the world. As a region, Latin America is the United States' largest trading partner.
Brazil has the largest economy in Latin America.
Mexico is also in this category. In 1995, the Mexican peso collapsed and brought the dollar down with it. U.S. financial markets took a hard hit. Singapore, South Korea, and Taiwan are struggling with the Asian Contagion. Losing 1 out of 3 businesses to the Y2K Bug may be too much for them to endure.