Although to younger generations of collectors the philatelic items that came out of WWII are postal history, to a large contingent of the collecting world -- the oldsters who were part of the conflict -- such items are souvenirs of a life changing and momentous time for the world and for them personally.
Many Baby Boomer collectors started their stamp collecting activities by accessing WWII material in the form of letters that relatives sent back from foreign lands.
Along with raiding letters sent home for stamps it was a way for the young to take part in the adventure and get a greater feel for what was happening than history books could give them. Of course a stamp collector with an interest in the WWII, Korea, Vietnam areas is lucky to find a trove of postal history.
Military Mail is an Unending Stream
Interestingly, those who came home and started a stamp collection, or continued one from earlier in their lives found, when they started to take an interest in military material, that it was not just WWII material they were collecting, but mail from many different strifes. It may be hard for those of a younger vintage, who went through the time of Vietnam, protests of which at home shattered the nation, to realize that there was no question about the rightness of the fight of WWII. Nearly every troop and combatant could legitimately feel like a hero, as he knew what he was doing was right.
Is it any wonder that the stamps and postal history of that time and place appeals to an older generation? Of course for dealers there's no down side to this. Not only does he get the buyers who legitimately study and enjoy the historical aspect of the area, but also those that spend their collecting budget money to reconnect sentimentally with "the best years of their lives."
Look at the continued popularity of patriotic covers of the era, some of them of questionable taste in their portrayal of racial stereotypes of the enemy. From today's perspective it seems quite wrong. But at the time these items played a role in undermining the enemy psychologically.
Military Mail Gets the Job Done
Not all mail from war is informative or exciting. In fact, for those who wish to reconstruct an historic record of the time it can be frustrating. But that is by necessity: mail full of information of troop movements, etc. that falls into the wrong hands can be disastrous. And so in modern wars collectors find so-called formula cards sent from military personnel that for security reasons merely allowed the sender to check off things like "I am fine" and "Arrived ok." Sweethearts and family awaiting word back home had to be content with the minimal information, as would collectors later, when such items found their way onto the collectible marketplace. The same is true of censored covers of course -- after the censor got done cutting out the interesting parts these letters resembled a doily -- and contained about the same amount of information as that decorative item.
But there was also V-Mail, a technological advance that encompassed photographically reducing letters so that more could be fit in the mail bags that contained letters home. Although they were enclosed in an outer envelope they were an early version of the USPS's Aerograms, light weight prepaid postage sheets that allow more economical mailing internationally.
A good place for the collector with a growing interest in WWII as seen through the lens of philately to begin is with the stamps issued by the U.S. in the years during and directly after the war. One does have to admire the stamps that were issued during and directly after the war years for the taste and self-controlled messages and presentation.