Indeed, Snoopy believing he was a World War I Flying Ace would have an impact on pop culture almost immediately. In 1966 The Royal Guardsmen would have a hit with the song "Snoopy vs. The Red Baron", which went to no. 2 on the Billboard Hot 100. As the band had failed to get Charles M. Schulz's permission, Quality Records in Canada refused to release the song there, so it was rewritten and re-recorded as "Squeaky vs. the Black Knight". Fortunately Charles M. Schulz eventually gave the song his blessing so it was released in Canada in its original form. The Royal Guardsmen released a sequel to "Snoopy vs. the Red Baron", "The Return of the Red Baron" in 1967 and later that year "Snoopy's Christmas". The band released one last Snoopy single, "Snoopy For President", in 1968.
The popularity of Snoopy as the Flying Ace was so great that when the Snoopy balloon made its debut in the Macy's Thanksgiving Day Parade in 1968 Snoopy was portrayed as the aviator. Snoopy would be changed to an astronaut in 1969, but the World War I Flying Ace would reappear as a balloon in the parade in 1979 and continued to appear until 1986. A new version of Snoopy as the Flying Ace appeared in the parade from 2006 to 2011. In 1966 a book, Snoopy and the Red Baron was published. There would also be two different video games--an Atari game titled Snoopy and the Red Baron in 1983 and a PlayStation 2/PlayStation Portable/PC game titled Snoopy vs. the Red Baron in 2006. Snoopy also appeared as the Flying Ace in several of the Peanuts TV specials as well as many, many bits of merchandise.
Snoopy's fantasy of being a Flying Ace locked in battle with the Red Baron was the end result of an evolution of the character over the years. When Snoopy first appeared in Peanuts on October 4 1950 (the comic strip was only two days old) he was a dog who walked on all fours. It was on May 27 1952 that Snoopy's thoughts were first conveyed via a thought balloon. It was only a few months later, on October 19 1952, that Snoopy was portrayed as dancing on two legs. On January 9 1956 he actually ice-skated across a frozen pond. Finally, on June 28 1957, Snoopy walked on two legs and would continue to do so afterwards. It would be in 1965 that Snoopy's fantasy life would start to develop, fantasising that he was a writer and a Flying Ace. By the early Seventies he would be Joe Cool and various other characters as well.
As hard as it is for many fans of Snoopy to believe, there are those who believe that Snoopy actually ruined Peanuts. In the article "Against Snoopy" published in the New York Press on January 4 2000, journalist Christopher Caldwell argued exactly that. The evolution of Snoopy from an ordinary dog to one who walks on two legs and has an active fantasy life certainly did change Peanuts. In its early days and even into the Sixties Peanuts could be a very dark comic strip, particularly for one about children. The characters of Peanuts could be selfish and even cruel to each other. Even Charlie Brown, who evolved into a down and out Everyman, could be mean at times. The characters, particularly Charlie Brown, often expressed very bleak and depressing views of the world. This was largely what set Peanuts apart from other comic strips that had come before it. While there had been intellectual comic strips before Peanuts (both Krazy Kat and Pogo come to mind), never before had anyone saddled children in a comic strip with existentialist angst.
The sheer bleakness of Peanuts certainly made the comic strip revolutionary and there can be no doubt that it was largely responsible for the comic strip's increasing popularity in the Fifties. At the same time, however, it made Peanuts sometimes a very depressing comic strip to read. It is perhaps for this reason that Charles M. Schulz started adding bits of whimsy to the strip as the Fifties progressed, such as the Kite Eating Tree and Linus's obsession with the Great Pumpkin. It is also perhaps why Snoopy began having his own thoughts, walking on two legs, and fantasising about being a novelist and a Flying Ace.
In my opinion, then, Snoopy actually improved Peanuts. As it originally appeared Peanuts was a brilliant and truly revolutionary comic strip. It was also a very depressing one. Reading an entire collection of those early strips one can be overpowered by the sheer bleakness of the early Peanuts. Snoopy brought balance to a comic strip that was in some ways overly negative. Here was a character who was generally optimistic, who had fantasies of being a World War I Flying Ace or Joe Cool, and who added a sense of whimsy to a comic strip that at times could be too dark. That is not to say that Snoopy was entirely at odds with the rather existentialistic vibe of Peanuts. In a 1997 interview published in The Comics Journal's December issue, Charles M. Schulz said of Snoopy, "He has to retreat into his fanciful world in order to survive. Otherwise, he leads kind of a dull, miserable life. I don't envy dogs the lives they have to live." In other words, Snoopy has a good deal in common with Walter Mitty or Billy Fisher of Billy Liar. He has a rich fantasy life because his real life is so dull.
Now that is not to say that I do not think the comic strip declined as the Seventies progressed. I do think giving Snoopy an extended family was a mistake--Peanuts seemed to grind to a halt any time his brother Spike appeared. At the same time many long running characters stopped appearing. Characters such as "mean girl" Violet and the narcissistic Freida appeared less frequently and eventually stopped appearing altogether (Violet in the Nineties, Freida in the Eighties). And while I like the character of Woodstock over all, in later years I thought he and Snoopy sometimes overwhelmed the comic strip. That having been said, I have to suspect that Peanuts would have declined even if Snoopy had never walked on two legs. Quite simply, it was not the focus on Snoopy that resulted in the comic strip's decline, but the fact that, like the Fifties, Peanuts was no longer balanced. Instead of too much existential angst, it was too little.
Regardless, Snoopy as the World War I Flying Ace certainly struck a chord with Peanuts' readers. Snoopy's fantasies of fighting the Red Baron had such an impact on popular culture that when many, perhaps most, people picture Snoopy it may be as the Flying Ace. As to why Snoopy's fantasy of being a Flying Ace proved so popular, I suspect it is because many people can identify with it. Quite simply, I think many people, if not most, at some point or another engage in daydreams to escape their otherwise drab and dreary lives. In some respects this makes Snoopy a more complex and deeper character than many of the other members of the Peanuts gang. Strangely enough, even though he walks on two legs and sleeps atop his doghouse, his rich fantasy life in some ways makes Snoopy one of the most realistic characters in the Peanuts canon.