Holocaust Memorial Day falls this week. Its theme is, Don’t Stand By.

It’s a day to remember the systematic, state-organised murder of six million Jews and millions of others, including Roma Gypsies, disabled people, homosexuals and the Nazi’s political opponents. We also remember subsequent genocides in Cambodia, Rwanda, Bosnia and Darfur.

Holocaust Memorial Day is a time to reflect on our global shortcomings. We recognise the absolute horror of the Holocaust and subsequent genocides, yet we allow them to recur with such depressing frequency.

Britain is justly proud of its role in the Second World War. Britain fought fascism, accepted 90,000 refugees from Nazi Germany before the outbreak of war and gave homes to more than 10,000 German Jewish children between 1938 and 1939.

By 1939, Jews trapped in central Europe were desperately seeking safety. Many surrounding countries, including Britain, placed limits on the number of refugees they would take, condemning others to certain death.

Europe once again faces a refugee crisis. Millions of Syrians are fleeing a terrible civil war and Isis wreaks another genocide.

David Cameron, we are told, is considering plans to admit 3,000 unaccompanied refugee children into the UK. Help the Children charity has pleaded for this for months.

Yvette Cooper, who chairs Labour’s refugee taskforce, said, “We must not turn our backs on refugee children; alone and at terrible risk. I met 11 and 12-year-olds living in the Calais ‘jungle’, alone, separated from their parents, incredibly vulnerable to exploitation, sexual violence, disease and cold. Every day the prime minister sits on his hands, more children disappear into the hands of criminal gangs.”

After the Holocaust, the world united and said, “Never again”. Those words have become an empty, sorrowful slogan, not our solemn pledge to current and future generations, fearful in the face of implacable brutality.