During WWII, the Royal Air Force deployed thousands of barrage balloons over British cities and factories to run interference with low-flying, divebombing German fighter planes.
In 1941, someone decided a bit of backstory might help English kids understand what all the balloons were for. Also, why buildings were exploding and everyone had to live in the basement. Or as Things Magazine put it with delightful understatement, a story that made an "attempt to familiarise children with extraordinary circumstances." The result that doesn't turn up anywhere else on Google: The Story of Blossom, The Brave Balloon, a children's book by E.F. Herbert with illustrations by Philip Zec.
I can't figure out who Herbert was, but his story leaves out the war itself--the man in the black aeroplane is "horrid," "rude," and "troublesome," that's about it--in favor of a bunch of pointless girl-pink/boy-blue silliness. Zec--and his artwork--are more interesting. He was a popular political cartoonist who managed to piss off both Hitler and Churchill. [Granted, only the former put him on a to-be-executed list.] I think his Blossom drawings kind of rock; they're much lighter and cleaner than his dayjob work, that's for sure.
Also, the idea of cuddly blimps reminds me of the awesome Friends With You "Sky Walkers" art balloon parade last December in South Beach.
See scans of the whole book, Blossom: The Brave Balloon, by E.F.Herbert and Philip Zec, Frederick Muller Ltd, London 1941 [thingsmagazine.net via]