Dishonest, inconsistent 'documentary'

Why do liberals always insist that Vietnam and Iraq are/were unjust and pointless, yet have absolutely no problems with WWI & WWII? It's very convenient of Sean Penn and Solomon to state that its only been in the 'last 50 years' that our presidents have used propaganda to lure Americans into war. In WWI our leftist president, a hero of liberals everywhere, Woodrow Wilson, made the greatest infringements on our free speech in our entire history, way more than Bush putatively did. And why did we enter the conflict? Well, to help out our buddies, of course. But objectively, what was the reason? Was the Kaiser a true, direct threat to US? Did he actually have any plans to bomb or invade US? No way. He just wanted to take over France and humiliate the British. It was more about power than anything else. The British and French, such humble people as they are, would never allow the 'Huns' to run Europe. Were the Germans committing serious, massive war crimes then? No. Did they have any genocidal plan on paper? No. Did they actually threaten US? No. Yet somehow, it's just a given that WWI was completely justified. Liberals rarely question that common historical wisdom. Our necessary involvement in WWII could also be challenged. Although I see WWII as justified and far more sensible than WWI, there are major flaws in our thinking towards it, also. Hitler made a major blunder when he declared war on us. But he never really had a plan against us. Other than small-scale espionage operations, and a failed bombing plan on NYC, Hitler and the Nazis had no serious ambitions concerning us, which would seriously threaten us directly. The conservative arguments in support of the Vietnam War and invasion of Iraq are that the governments in both countries were threats to us, because they had WMDS and links to terrorists who DID attack us, or were trying to take over the world, one 'domino' at a time. I agree with both arguments. But liberals argue that neither country actually directly threatened us. If that is the case, how the heck did Third Reich Germany? Sure, their U-Boats were attacking all US and British ships in the Atlantic before we officially were at war, and sure, Japan attacked our largest naval base at Pearl Harbor, but how did those events constitute real, solid threats to all of us, Americans? One could credibly argue that both German and Japanese aggression against us were minimal and not meant to engage us fully in total war. After all, Japan was angry that we did an oil blockade on them, when we formerly supplied them with most of their oil. Japan just wanted control of China and the Pacific, also. You could easily say we acted more out of power politics and self-righteous imperialism than morals or objective threats. If we did not react to Pearl Harbor, after all, would Japan bomb us again? If we backed off from Britain and left them to themselves, would Germany attack us? Who knows. But one could easily and credibly argue that the Axis powers really were no threat to America.