Before delving into the current controversy about Polish-Jewish relations before, during and after the Holocaust, there is a point of principle that requires clarification: should a government, or a parliament, decree the facts of a disputed past? Certainly, it may be justified to criminalize statements that deny universally accepted truths. Some countries, including Israel, have laws on their books that punish those who deny the Holocaust. Others, such as the US, have adopted the attitude that unless personal damage is threatened, even the most loathsome statements may be made, so that they can be refuted in public. Had the Polish authorities enacted a law stating that whoever denies the fact that Nazi Germany occupied Poland and there instituted an almost six-year reign of terror should be hauled in front of a court, one might perhaps find reasons to accept that. But the Polish state has decided it has the right to define what it calls “facts,” as determined by partisan academic and political forces supporting its present government, as well as its current parliamentary majority.Let me be very clear: History should be discussed openly and freely, and no government has the slightest right to dictate the past. In Israel, if you write that all members of the Judenräte (Nazi-appointed Jewish councils in ghettos) were traitors, or that the Warsaw Ghetto Uprising was a harmful exercise that endangered the remaining Jewish population, you may be (rightfully, I believe) attacked in the media and academia, but no one will deny your right to say what you wish. The attitude of the present Polish authorities is reminiscent of the country’s communist past – it has the flavor of an anti-communist Bolshevism. Its practical expression is a controversial amendment to an existing law, and it is absolutely unacceptable.An extremely worrisome development is emerging from official Poland: the rewriting of history. Their argument, in general, is that yes, there was some prewar antisemitism in Poland, but generally there was peace and harmony, continuing the coexistence between Poles and Jews since medieval times. Under German occupation, Polish society, itself under attack, supported the Jews, albeit with some exceptions; there were huge numbers of rescuers, represented by the Polish government-in-exile and the Polish underground.Plainly, these are inventions. Between the world wars, though there was an important minority among the Poles opposed to antisemitism, the majority was increasingly hostile. In the late 1930s, there were pogroms and government-supported boycotts of Jews. During World War II, the Polish nation was exposed not to extermination, as the Jews were, but to enslavement – a clear case of genocide, but a radically different one from that which we call the Holocaust. A tremendously courageous but small minority of Polish rescuers were exemplars of selfless humanity. Nevertheless, the majority was anti-Jewish, gladly exploiting the murder of the Jews by robbing their property. Many – certainly not all – Poles, especially among the peasants, either murdered Jews or delivered them to the hands of the collaborationist Polish police, or straight to German murderers.Polish revisionists present invented statistics. In recent correspondence with Rabbi Shmuley Boteach of New Jersey, Polish Prime Minister Mateusz Morawiecki claimed that out of 3.3 million Polish Jews at the war’s outbreak, 300,000 survived, and for that most of Polish society must be credited. In fact, of those 300,000, well over 250,000 survived the war in the Soviet Union, not in Poland; the real number of Jewish survivors in Poland itself is estimated to have been approximately 40,000.A new Polish claim is that every rescued Jew was helped by at least 10 Poles. There may be some truth in that, but then, almost every rescuer rescued more than one Jew. This kind of numbers game is an obscenity that denigrates both the rescued and the rescuers. If this argument were correct, then there would hardly be any Righteous Among the Nations, because everybody was just dying to rescue Jews. The truth is the Polish Righteous were selfless heroes who had to contend less with occupying German forces than with their own opportunistic and ruthless Polish neighbors.Sadly, there is truth in the Polish contention that there are Jewish extremists who detest Poland and everything Polish. These are condemnable stereotypes. Democratic Poland is a friend. Yad Vashem, and other communities of Holocaust researchers and educators around the world, continue to maintain close ties with many Poles. We welcome and encourage our ongoing cooperation with Polish groups and institutions on various historical matters, including the preservation and establishment of memorials, discovery and accessing of documentation, and teacher training.The controversy is not with the Polish nation, but rather with an extreme, nationalist invention of a past that was actually very different from what Polish officials now espouse. A new, distorted history is being presented, and there is a danger that this invented history will be taken seriously beyond Poland, Israel and the Jewish world.This issue goes far beyond controversial legislation. If we permit the radical distortion of our joint past, there can be no shared present and there will be no common future.The author is the academic adviser of Yad Vashem.