The question, from today's editorial in the LA Times:

The interesting question is why the U.S. economy, beneficiary since 9/11 of the largest military spending binge in history, now requires $150 billion more in the form of a short-term stimulus package. Why hasn't the $1 trillion in defense spending, in addition to the 2001 and 2003 tax cuts, been sufficient to keep the economic boom going?

The answer, from Economist's View commenter, James Kroeger:

The answer should be apparent to any Democrat[ic] Economist. The incredible borrowing spree of the past several years has really been the only thing that kept the economy from collapsing into a Greatest Depression Ever as a direct result of the massive tax cuts Bush et al. gave to the rich. Reducing the income tax rates of rich people is always CONTRACTIONARY.

I strongly recommend reading Kroeger's entire comment here. One of this country's biggest exports has been money.