I've just watched the story and to be honest, it only reinforces my hatred of them. A poster that was never used because we were never being invaded is being used in the current day all over the country when in fact we're the ones doing the invading. Try sending the poster to Iran and Afghanistan and Iraq, see what they think of it. If war started nowadays and the government started to re-print that poster, I'd tell them to eff off haha!
Couple that with the fact that every man and his dog has had a go at doing some variation of it, showing the how widely spread the lack of creativity in this country (and others now jumping on the bandwagon!) goes, it's the only thing that actually does the EXACT opposite to what it says to me lol! I'm usually quite a calm person, this makes me blood boil! Perhaps that was the original intent, I mean, that would be pretty clever - we're at war, don't keep calm and carry on, go kick the bejesus out of the enemy!