The lives of a Nazi collaborator and a woman who helped to hide Anne Frank illuminate the history of the Holocaust.

Earlier this month, on 11 January, two individuals whose lives were bound up with the story of the Holocaust died. One was male, the other female. The former was born and lived in Estonia but later fled to Finland and Sweden and ultimately found refuge in Venezuela, where he became a multimillionaire. The latter was born in Austria, but lived in Holland throughout the Nazi occupation and remained in Amsterdam for the rest of her life. Both were ostensibly minor figures during the years 1939-1945, but became better-known after the war as news of their deeds was publicised. One was a Nazi collaborator, the other a "Righteous Gentile".

I am referring to Harry Mannil, who served in the dreaded Estonian political police, which carried out the arrest and execution of numerous Jews and communists in Tallinn during the initial year of the Nazi occupation and to Miep Gies, who played a critical role in hiding Anne Frank, her family and four additional Jews from the Nazis in Amsterdam and was the person who saved Anne's diary. While neither had a prominent position, it would be instructive, as we approach Holocaust Memorial Day to take a closer look at their activities and the decisions they made during the war to focus on the important lessons we can learn from the fate of European Jewry during the Holocaust.

In that respect, the most significant fact to keep in mind about the Holocaust is that it was not an unavoidable natural disaster, but a tragedy created by human beings. It did not have to happen and might have been prevented if the right decisions had been made. And that is why there is so much to be learned from its history and why the work of organisations such as the Holocaust Educational Trust are so vital. It was decisions made by human beings at every level that determined the fate of so many people and that is why it is illuminating to contrast two people like Miep Gies and Harry Mannil.

They were both relatively young when their countries were invaded by the Nazis (Miep was 31, Harry 22) and probably had no inkling that the war would create situations in which their decisions would influence the fates of numerous Jews. Harry Mannil decided to join the Estonian Nazi collaborators of the notorious political police, which helped implement the Nazis' plan to annihilate all the local Jews and eliminate the communists. He was involved in arrests and interrogated at least seven Jews who were subsequently murdered. In that capacity, he was part of the machinery of destruction that rendered his homeland Judenrein ("free of Jews" in Nazi parlance), as noted in the protocol of the infamous Wannsee Conference at which the Final Solution was officially discussed. In contrast, Miep Gies chose to assist those persecuted by the Nazis and risked her life to try and save the eight Jews in the Frank family hiding place, only one of whom ultimately survived.

The events of the second world war and the Nazis' determination to annihilate all of European Jewry put the nations of the world to serious tests of morality and integrity. The manner in which they responded determined the fate of millions. The countries allied with Nazi Germany had to decide whether to turn over their Jews over to the Nazis while those in the free world had decide whether to help save them by admitting them as refugees while emigration was still possible. But there were also much more prosaic dilemmas faced by those in occupied Europe. And it was under those circumstances that individuals could make a difference in saving lives or murdering innocent people.

That is why it is essential to remember people such as Miep Gies, a model of humanity and selfless sacrifice, but also never to forget those such as Harry Mannil, who chose to join the killers. Like millions of Europeans, their decisions made a difference in determining the fates of their Jewish neighbours, a lesson which should serve as an important warning to all of us and to future generations.

guardian.co.uk