“All You Need Is Love” is worse than hypocrisy. It is the wrong strategy, especially in the worst cases:
War is not fashionable among moral exhibitionists. However, as the Romans noticed more than 2,000 years ago, those who really love peace, prepare for war (Si Vis Pacem, Para Bellum).
After the dictatorship of Kaiser Wilhelm II suddenly attacked the world on August 1, 1914, Earl Grey the British Foreign Minister, went to the Commons, and made an excellent speech about joining the war to defend civilization. Bertrand Russell, the philosopher, understood none of it (because like Keynes, or the Kaiser, Russell was on the plutocratic side).
War can be a horrible thing. Even for warriors.