London — It is not a commonly known fact that the Nazi's most westerly concentration camp during World War II was on a remote, tiny island that belongs to Britain. But on Wednesday, 80 years after the isle of Alderney's liberation from Adolf Hitler's forces, Britain's Post-Holocaust Issues Envoy revealed that as many as 1,134 people likely died there — and that "a succession of cover-ups" by post-war British governments tried to obscure the failure to prosecute Nazi officers responsible for war crimes on U.K. soil. Just off the coast of northern France, Alderney is one of the lesser-known Channel...