While there are, of course, enormous differences between the big picture war on terror and the Cold War and the smaller picture war in Iraq and the Vietnam War, there are also uncanny parallels that might enhance our understanding of today's global conflict.
In the Sixties and Seventies, liberals and conservatives disagreed on whether Vietnam was in a civil war or a victim of the Communists' plan for global expansion. The left seemed all too eager to ignore that both the Soviet and Chinese communists were funding and fomenting North Vietnam's aggression, just as the left today wants to ignore Iran's and Syria's similar sponsorship of terrorism and ethnic strife in Iraq.
Indeed, liberals argued that there was no monolithic communist movement -- given the competing communist power centers of the Soviet Union and China -- and dismissed fears born of the domino theory: that if South Vietnam were to fall, other nations would do likewise. Much of the left today tells us that because there is so much internecine conflict among Muslims, mainly between Sunni and Shia, that we shouldn't fear their pursuit of a global caliphate. Liberals today view the Iraq war in a vacuum, denying it is part of the global war on terror and downplaying the likely devastating consequences for Iraq, the Iraqi people and the war on terror if we prematurely withdraw from Iraq.
We lost very few battles in Vietnam, yet the left and the media convinced the American people we were losing the war, which eventually eroded our will. We have lost few, if any battles in Iraq, but the conventional wisdom emanating from the left and the mainstream media is that we are losing the war. Consequently, America's will to persevere has been severely compromised.
Cold War liberals pooh poohed Nikita Khrushchev's "We will bury you" threats to the United States, and ridiculed conservatives as fearing that communists were "behind every rock." Today's liberals also seem unwilling to take Iranian President Mahmoud Ahmadinejad at his word that he is committed to exterminating ("burying") Israel. Bill Clinton and John Kerry, to name a few of today's libs, have made fun of conservatives for believing there are terrorists behind every rock.