With tensions rising in Korea, too, it is hard to believe President Obama will bolster ground forces on the peninsula, when even Donald Rumsfeld was presiding over a drawdown and a shifting of U.S. troops away from the DMZ.

In Latin America, the United States seems reconciled to the rise of an anti-American radical-socialist coalition, led by Venezuela's Hugo Chavez and embracing Bolivia, Ecuador, Nicaragua and Cuba.

Partisans of President Bush may blame Obama for presiding over a strategic retreat, but it is the Bush administration that assured and accelerated such a retreat.

As Robert Pape of the University of Chicago writes in The National Interest: "America is in unprecedented decline. The self-inflicted wounds of the Iraq war, growing government debt, increasingly negative current-account balances and other internal economic weaknesses have cost the United States real power in today's world of rapidly spreading knowledge and technology. If present trends continue, we will look back at the Bush administration years as the death knell of American hegemony."

Pape's harsh verdict is rooted in his reading of history, that the "size of an economy relative to potential rivals ultimately determines the limits of power in international politics."

In other words, when a great nation's share of world product shrinks, the nation's strategic position follows. Between 2000 and 2008, the U.S. share of world product plunged from 31 percent to 23 percent, and is expected to fall to 21 percent by 2013 -- a decline of 32 percent in 13 years. China's share of world product over the same period will more than double to 9 percent.

Pape went back to the 19th century to correlate the rise of the great powers like Britain and the commensurate growth in their share of world product. He found the Bush decline had no precedent.

"America's relative decline since 2000 of some 30 percent represents a far greater loss of relative power in a shorter time than any power shift among European great powers roughly from the end of the Napoleonic Wars to World War II. It is one of the largest relative declines in modern history. Indeed, in size, it is clearly surpassed by only one other great-power decline, the unprecedented internal collapse of the Soviet Union in 1991."

With an economy still three times that of China, America continues to be the world's most powerful nation, fully capable of defending all of its vital interests. We can no longer, however, defend every ally to whom we made a commitment over the six decades since NATO was formed.

Obama's assignment: Rebuild U.S. productive power, and execute a strategic withdrawal from non-vital commitments.