Oh but I’ll stay, if you promise to keep me safe

The First World War is sometimes referred to as the Last Gentlemen's War. It was the last war of Imperial alliances, not least of all because it was the end of many of the Empires involved. It also held the seeds of what made the Second World War different from anything that had come before it. Not so much the technology - the tanks, bigger and better guns, aerial warfare - but the mentality. WW1 saw the germination of ideas about camouflage and disguise and propaganda, making things seem different than they really are. World War Two was a battle of wits.

( Churchill's Wizards by Nicholas Rankin )