All of the things that are noted above seem to be right on the "money." (Sorry.) For many years we have seen how the U.S. dollar changes in relation to other countries. If the dollar is weak, it is not worth as much in other places (currency conversions). Devaluation is when currency loses its strength. Some analysts believe that when a devaluation takes place it can boost the economy by promoting more manufacturing.
If our dollar is faltering, the only places where the dollar is strong is in economies that are worse off than our own. When the dollar is strong, the economy is strong. The mention of Greece is a perfect example of the effect of a country's economy and struggling currency affecting other countries who are tied to the failing country and its currency (and its economy's difficulties). This seems simply a larger example of what we have been experiencing in our country as we have seen our government bail out banks, etc. Overall, when the currency of a country becomes unstable, people stop investing in that country. If there is already a economic crisis in that country, this will only make it worse.