Peace in Japan and Germany came along with support from allies. Taxes were raised and the public at large was asked to sacrifice during wartime in order to fund those victories. There were clear goals that needed to be achieved and enemies with borders who needed to be defeated. Most importantly, people from all walks of life knew what needed to be done to achieve victory.
With everything that has happened so far, especially with who we have in charge, there's no way you could argue that victory in Iraq will be as clear cut as it was in Japan and Germany. What exactly is victory for you? Who and where exactly is the enemy? How can you generate public support for this war considering its fabricated origins that the people in charge have still not admitted? When will there be enough security in order for diplomats to do the real job of healing a divided country? How will we pay for this war without driving up inflation and/or borrowing from China?
Before the war began, conservatives believed that WMDs were a threat to the free world, ignored the UN Weapon Inspectors, and invaded anyway. When top ranking generals predicted that we needed a massive force to handle the aftermath, conservatives brushed them off. When WMDs were never found, conservatives said that the war was justified in order to overthrow the evil dictator Saddam and give Iraqis freedom. When Saddam was overthrown, conservatives wanted to hand over military responsibility to the Iraqis. Instead, we're sending more troops into Iraq because somehow, soldiers with guns alone are supposed to solve a diplomatic divide. And all this time, how many times have conservatives been right or even fessed up to being wrong?
Conservatives have argued that the cost of losing in Iraq will lead to more 9/11's and that is why we need to stay. I'd ask for some evidence, but I don't exactly trust the filter it's coming from. We need to stay, when Osama bin Laden and the Taliban cited American intervention in the Middle East as the primary reasons for the 9/11 attacks in the first place. And now they're rallying around McCain because somehow, he has the "credibility" and "experience" to magically fix everything with the wave of his victory wand. Somehow, we have to defend the honor of America for the sake of saving face at the cost of American lives, influence, and power.
In conclusion, conservatives in charge and those who support them are taking a piss on America and convincing everyone it’s raining.