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.

Cold War liberals habitually apologized for Soviet Communist aggression and their obsessive pursuit of nuclear weapons. They maintained there was moral equivalence between the United States and the Soviets in the arms race and insisted the Soviet regime was not inherently evil, but merely protecting its interests -- from U.S. imperialism. If we would just freeze our nukes, then disarm, the Soviets would follow. Today's terrorist apologists insist that Muslim extremists have legitimate grievances, including the alleged dispossession of Palestinians from "their" land and American "imperialism" in Iraq. If Israel would just give back the land and we would withdraw from Iraq, the terrorists' thirst for bloodshed would be quenched.

The left today -- like yesterday -- can't get its head around the idea that we are in a global war, and that is primarily because it has difficulty making the crucial moral distinctions that are essential to our clarity of vision.

Its inability or refusal to see Islamic extremism as evil prevents it from understanding that the terrorists' hostility against us, Israel and any other nation that chooses to obstruct their hegemonic designs cannot be appeased and that they must be defeated.

The left's blindness to this evil keeps it from grasping that we are not the antagonists in Iraq or the initiators of a "war of choice," but justifiably removed Saddam Hussein from power and are now morally justified in trying to help the Iraqis establish self-rule. The liberals' blindness also led them to sympathize with misguided European and United Nations' critics of the U.S. intervention in Iraq.

When the left finally succeeded in de-funding our defense of South Vietnam, a bloodbath ensued, despite John Kerry's and the left's arrogantly cynical dismissal of predictions it would occur. The left has never been held accountable for that, partly because it distorted and rewrote history, and as a result it has far more credibility than it deserves today in advocating a similar withdrawal from Iraq and in denying the abject evil of Muslim extremists.

To glean the proper lessons from these parallels we must compare the approach of the left toward our enemies -- best personified in Jimmy Carter's defeatism and malaise (which still persists today) -- to the triumphalism of Reagan conservatism.

Had America accepted the Jimmy Carter worldview, we might still be fighting the Cold War. Until we reject that worldview today and understand the nature of our enemy and the global context of the war, we will be hard-pressed to turn the corner in the war on terror.