answer:If the Euro falls apart, it will affect the banks that hold European debt. That debt is held as an asset on the banks books and has to b written off, then those banks either fail or cannot lend any more money, causing the credit market to collapse. When that falls apart it triggers problems all over the world. US banks, Japanese banks and Chinese banks, and investors in European markets, will lose money and their economies contract. Europeans would not be buying anything made outside the Eurozone because of no ability to pay for it. That would all be a major hit to all economies.