High school textbooks in China apply the language and imagery of the Holocaust to Japan's Nanjing massacres of 1937, while Japanese textbooks use similar language to depict the devastation caused by atomic bombs in Hiroshima and Nagasaki at the end of World War II, according to a recent study comparing the way textbooks in 139 countries and territories teach the Holocaust – or ignore it.

Twenty-eight countries make no reference to the Holocaust in their curricula, including Western countries like New Zealand and Iceland as well as Bolivia, Thailand and Muslim areas including the Palestinian territories, Egypt and Iraq, the study found. In some of these countries, curricula do not stipulate specific content for history education.

The research, conducted by Germany's Georg Eckert Institute for International Textbook Research and published by the UN Educational, Scientific and Cultural Organization, was released ahead of International Holocaust Remembrance Day on Tuesday, which commemorates the 70th anniversary of the liberation of Auschwitz-Birkenau.

The study found that the curricula in countries like China and India show that historians "'tragedize' their own pasts by conspicuously re-contextualizing vocabulary customarily used to describe the Holocaust, including 'terrible massacres,' 'killings,' 'mass murders,' 'atrocities' and 'extermination,'" writes Eckhardt Fuchs, the deputy director of the Georg Eckert Institute.

Another country that uses typical Holocaust terminology to describe local atrocities is Rwanda, in textbook descriptions of the genocide of 1994. In India, references to the Holocaust vary widely, depending on the political context in which the textbooks were published.

For instance, a textbook published when the federal government was under the control of the Left Front, an alliance of leftist parties, associates Germany's territorial expansion with European colonialism in Asia, while one that reveals sympathies with the nationalist Bharatiya Janata Party and its attempts to establish an undivided India through militarization, industrialization and the "sons of the land" – ideals that echo those of the Nazis – doesn't mention the Holocaust at all.

The textbooks in 57 countries, including the United States, Canada, Brazil, Germany, Poland, France and Turkey, describe the Holocaust directly, using the words "Holocaust" or "Shoah."

Fifty-four countries, including Norway, Algeria and Peru, provide only the context in which the Holocaust may be taught (for instance, by referring to World War II or National Socialism) or address the Holocaust only to achieve an educational objective that is not specifically related to the Holocaust, as Mexico, Colombia and Argentina do.