Translate the following English sentence to French:
"How is it that all the European institutions and the people in them agree to what, under the laws of the 15 Member States, constitutes a serious criminal offence, in the narrow sense of the word, and is liable to punishment as such?"
Mais pourquoi toutes les institutions européennes et les hommes qui les composent acceptent-ils ce qui constitue dans les législations des 15 États membres une infraction pénale grave, au sens strict du terme, passible d'une peine criminelle ?