The first of a series of economic shock waves have reverberated across the Pacific following the catastrophic earthquake and tsunami in Japan. Outsourcing U.S. manufacturing may not have been such a good idea after all.

General Motors Co. says it has shut down production at its Shreveport plant in Louisiana for the week of March 21. The factory closing was necessitated because the “factory” ran out of parts that were made in Japan.

The American “manufacturer” says it still has enough Chevrolet Colorado and gmc Canyon trucks to meet current demand. However, the shutdown could be a precursor to shutdowns by other U.S.-based assemblers who are reliant on imported components.

GM said that its other plants continue to run normally.

But the shutdown of a factory building a product that is the archetypal symbol of American manufacturing power raises an important question. How many other “American made” products are reliant on foreign-manufactured goods?

And is America becoming more of an “assembled in America”-type country?

The answer to that question has implications that go far beyond just the retention of factory jobs. It is an indicator of the nation’s economic strength. For more information on the danger of foreign dependence, read “Shooting Ourselves in the Foot” and “The Death of American Manufacturing.”