It's called globalization. I always make a point of having at least a third of my portfolio invested overseas. So?
As long as its a publicly traded company, wherever it's based, wherever it has operations, you can bet it's partly domestically owned, and partly foreign owned.
Back when protectionists were howling about 'foreign automakers' my take was always, "So? Buy Honda, Nissan or Toyota stock."
Global corporatism is sucking the life's-blood right out of this country. Our nation, and its economy were built by domestic entrepreneurs, not multi-national CEO's whose only concern is raising stock-prices for the benefit of speculators (who somehow fancy themselves as capitalists) while having no personal investment in building real value in the company, its employees, or society.
Precisely because of globalization, the diversification benefits of international investments have been significantly reduced over the past decade. While it is true that a decade or so ago financial professionals would advocate investments in international equities and fixed income securities as a tool for diversification, recent empirical studies show that correlations of returns between domestic and foreign assets have been consistently increasing and hence, reducing diversification benefits. Foreign investments have additional risks such as foreign currency exchange and country credit risk which ought to be weighted against decreased diversification benefits and expected return.