This isn't a book of mystical, Nostradamus-like predictions; Friedman is the founder and CEO of STRATCOM, a private intelligence firm. I read his previous book, The Next 100 Years, last year and found it fascinating. This book is even easier to grasp since it relates to a shorter time period. Friedman talks about how the United States has to accept its imperial role whether Americans like it or not. He says the best way for the U.S. to manage world affairs is to set regional rivals against each other to maintain a balance of power. For example, Iran and Iraq filled that role in the Middle East. For decades, the U.S. maintained balance by offering assistance to one side or the other depending on which needed help the most. Unfortunately, the "war on terror" has undermined this strategy by weakening Iraq (it has also weakened Pakistan, which has served as India's foil in southern Asia). We are already seeing a resurgent Iran attempting to fill the power vacuum.
In addition to predicting the future, Friedman provides ample education about how current geopolitical situations have developed. While many Americans think the Arab nations are against us because we support Israel, Friedman explains how those nations actually turned against us by siding with the Soviets before we threw our support to Israel. Regardless, he suggests that we reconsider aid to Israel because it is no longer a weak state that needs our assistance. He notes that although U.S. aid has remained more or less constant, it was about 21% of Israel's GDP in 1974 whereas now it is about 1.4%.
Although my examples above are from the Middle East, Friedman covers every region of the world thoroughly. The Next Decade and The Next 100 Years are must-read books for anyone interested in geopolitics. While I consider myself more aware of international affairs than most Americans, I still learned a lot from both books.