False diversification and the U.S. world position

[Wayfare]

While all reasonable investors are diversified somewhat in the stocks / industries they have positions in, almost all of these stocks are usually (in my experience) in U.S. markets. Why are we all so confident that the United States will continue its run of stability and sustained growth? If there is a catastrophic change in the U.S. economy, our "diversification" would be completely hollow. Some points that cause concern.

Biggest ever trade deficit / budget deficit

Foreign direct investment "Bubble"

Long-term fiscal insolvency issues

Continuing target in escalating battle with terrorism

Political leaders with questional ability to handle situation acceptably

The doomsday scenerio is that some event (financial report, scandal, terrorist attack) causes panic in the United States and leads to foreign capital flight. This would lead to dollar depreciation and a loss of purchasing power and ability to pay back our foreign debt.

WSJ wednesday says that while other countries have been devestated by financial conditions similar to that of the United States (in terms of deby and current account deficit) but that the United States is "special" due to its high FDI and position in the world. Today WSJ skeptically asks whether America will be able to sustain its FDI growth indefinately, which has risen from $175B to $700B+ in the last ten years.

Anyone else worried enough to start heavily diversifying internationally? I am.