Germany did win the war. They were liberated from the Nazi regime, they regained most of their geography. The country was rebuilt with the generosity of other countries. And now, despite the fact that gasoline cost $12 a gallon there, it is one of the wealthiest countries in the world and it's economy is still growing.
How are they able to have such a healthy economy when petroleum, something that germany doesn't produce at all, is so expensive? Petroleum has more influence on the US dollar than the US federal banks. The price of oil goes up, and the value of the US dollar goes down. We should learn something from Germany.
Regarding Tet. The tet offensive was a victory for the communist insurgents, even though it was a military defeat. In terms of warfare, the forces of South Vietnam and the forces fighting on their behalf were winning the war day after day, year after year, untill the South was defeated.
The point is, and even today some very important people don't get this, is that you can't militarily win a war against guerrilla insurgency. It's not something that can be defeated by physical attrition. The way to defeat a guerrilla insurgency is by making the insurgents irrelevant. What that means is that you have to secure the populace against the terrorism of the guerrillas to the point that the populace has confidence in that security and in the forces providing it. If the people don't believe that the security forces are commited for the long enough term, they're not going to risk contributing anything. Securing the populace requires significantly more man power, yet monetarily the cost is less than attrition warfare. There are many many examples in vietnam where the destruction of a handfull of rice eating, sandal wearing, sks toting guerrillas cost the US tens and hundreds of thousands of dollars. Obviously this is not a sustainable strategy, and it wasn't. The solution takes time and alot of men, but not necesarilly an expensive arsenal. You have to make the populace secure from the guerrillas and keep it secure untill the futility of the guerrilla situation disolves the ranks and will of the insurgents and their proponents to the point where the movement collapses and dissolves back into criminal cells small enough to be managable by the police agencies. Take, clear and hold is a ridiculously simple concept, appearantly unfasionably simple. But it works, it just demands time and commitment.