I'd say comparisons are still not only valid, but absolutely required to put the conflict into perspective.
And we haven't always been willing to pay the price. In fact, WWII is a good example, in many ways. We could have stopped the Axis several times before the big one broke out -- the Rhineland, Spain, Libya. But the US public was against getting involved.
Even once the big one started -- Americans didn't care about saving France, England, etc, from the Nazi boot. Only when we, specifically, were sneak attacked militarily by one of the Axis powers did we even lower ourselves to finally take a side and fight for whats right.
I'm afraid the paralells to WWII are not only instructive, but frightening.
The historical event that we call World War II began as a long-standing conflict between two different forms of Marxism/socialism on the European continent -- the nationalist (German) model and the international Communist (Soviet) model. In stark, objective terms, you cannot even make the case today that the U.S. fought on the "right" side in that war (consider that the death toll in Eastern Europe under Stalin exceeded the death toll in all of Europe under Hitler's Nazism).
The Spanish Civil War was a perfect case in point. Most Spanish who supported Franco were well aware of what this national fascism was all about, and they found it a perfectly acceptable -- even desirable -- alternative to the brutal totalitarianism that prevailed under the Spanish communists.