If you're kind of shakey about investing totally in US companies, including some international companies into your portfolio is a good idea.
I am getting the uneasy feeling that the Euro will become the future currency that will be used to value oil. If that happens the Dollar's value will no longer be supported by all the countries in the world who now have to purchase their oil based on it.
The current policies of the US Government are creating a huge amount of debt, this is putting great pressure on the Dollar's strength.