On Wednesday, Joe Lieberman wrote on this page that the Democratic Party he and I grew up in has drifted far from the foreign policy espoused by Franklin Roosevelt, Harry Truman and John Kennedy.

In fact, it is the policies that President George W. Bush has pursued, and that John McCain would continue, that are divorced from that great tradition – and from the legacy of Republican presidents like Ronald Reagan and George H.W. Bush.

Sen. Lieberman is right: 9/11 was a pivotal moment. History will judge Mr. Bush's reaction less for the mistakes he made than for the opportunities he squandered.

The president had a historic opportunity to unite Americans and the world in common cause. Instead – by exploiting the politics of fear, instigating an optional war in Iraq before finishing a necessary war in Afghanistan, and instituting policies on torture, detainees and domestic surveillance that fly in the face of our values and interests – Mr. Bush divided Americans from each other and from the world.

At the heart of this failure is an obsession with the "war on terrorism" that ignores larger forces shaping the world: the emergence of China, India, Russia and Europe; the spread of lethal weapons and dangerous diseases; uncertain supplies of energy, food and water; the persistence of poverty; ethnic animosities and state failures; a rapidly warming planet; the challenge to nation states from above and below.