If during the Cold War we had let the key features of our formula for greatness - which are the major determinants of economic growth and therefore of power and influence in the world we are living in - deteriorate the way we did during the Terrible Twos, it would have been considered the equivalent of unilateral disarmament. Politicians would have accused one another of creating or tolerating an 'education gap' or an 'infrastructure gap', like the 'missile gap' of the 1950s. The charges and countercharges would have dominated national elections. In the Terrible Twos, something far worse happened.
We didn't notice. Declining numbers in the important categories of national life became normal.
Then we made things even worse. Having underestimated the challenge posed to America by 11/9 - November 9, 1989, the day the Berlin Wall fell - we compounded the error by overestimating the challenge of 9/11. We spent the rest of the decade focusing our national attention and resources on the losers from globalisation - al-Qaeda, Iraq, Pakistan and Afghanistan - when our major long-term challenge comes from the winners, most of them in Asia. We devoted ourselves to nation-building in Mesopotamia and the Hindu Kush when we should have been concentrating on nation-building at home.
Since the authors of this book both supported the war in Iraq ... we need to say what we got wrong and what we still believe. Both of us believed then and believe now that finding a way to bring democracy into the heart of the Arab world was a strategic and moral imperative. We knew it would be difficult and costly, and said so at the time, but even so, we underestimated just how difficult and how costly. We have nothing but regret for the excessive price that America and Iraq have had to pay in lives and treasure.
The losers from globalisation - specifically al-Qaeda and Saddam Hussein - did pose significant security problems. We had to strike back against al-Qaeda, perpetrators of 9/11, not simply to deter another attack but also to disrupt what they might have been planning next. But Saddam Hussein was not part of 9/11. The Bush administration asserted that his regime had to be toppled because it had weapons of mass destruction. Neither of us shared that view. Michael believed that the weapons of mass destruction that Saddam Hussein was thought to possess - chemical weapons - did not pose a severe enough threat to justify an attack. What did justify removing him from power was the prospect that at some point he would acquire nuclear weapons.
Tom's view was that the long-term threat to the United States from the Middle East came less from weapons of mass destruction than from people of mass destruction, produced in a region where autocratic regimes were stifling and enraging the people they governed. That was his view in 2001, not just in 2011, when uprisings around the Arab world occurred, triggered by deep frustration and anger at the long-ruling dictatorships and motivated as well, in many cases, by democratic yearnings. His hope was that America could collaborate with a free Iraq to create a decent, democratic model of development in a region that had none.
It was neither foolish nor irresponsible for President George W Bush to want to use Iraq as a lever to pry open the closed and autocratic world of Arab politics. It was, however, both foolish and irresponsible to try to do so without an adequate understanding of the scale and complexity of what was required. Execution matters.
America's initial policy in Iraq offers, alas, a metaphor for much of American public policy in the Terrible Twos: Our reach exceeded our grasp and ability to execute. We simply, casually and wrongly assumed that things would work out. We willed the ends but not the means.
This is an edited extract from That Used to Be US published by Little, Brown Book Group, distributed exclusively in India by Hachette India
Thomas Friedman is a Pulitzer Prize-winning journalist and author of The World Is Flat. He will be a speaker at The Think Fest in Goa, November 4-6.
Michael Mandelbaum is director, John Hopkins University School of Advanced International Studies and the author of The Ideas That Conquered the World.