Each year on April 24, Armenians around the world celebrate Genocide Remembrance Day. Between 1915 and 1923, 1.5 million Armenians were slaughtered by the Ottoman Empire.

Yet more horrific than the atrocity itself is Turkey’s ongoing denial of its responsibility for this major crime against humanity.

Today, the Turkish government denies that the genocide occurred, even though it is remarkably well documented. The country’s penal code sentences any Turkish citizen who questions the official account to a prison sentence between six months and three years.

For decades, Congress refused to recognize the Armenian Genocide as such, because Turkey is perhaps the United States’ most loyal ally in the Muslim world. Yet this year the House Foreign Affairs Committee finally acknowledged Turkey’s responsibility for the first major European genocide of the past century.

Turkey wants to join the European Union. Many Europeans do not like this idea because only 3 percent of Turkey’s territory is in Europe and because of its Muslim heritage.

This is not my main objection to their joining of the European family. Muslims have played an important role in the development of Western civilization, and Europe is more of a cultural construct than a geographic reality.

The European Union and NATO are governed by the rules of democracy and pluralism.

Turkey continues to persecute its Armenian and Kurdish minorities. For it to be an ally of the U.S. against Islamic fundamentalism and prove that Islam and the secular state can be reconciled and enter Europe, it must make some serious changes.

What kind of democracy tries to jail Orhan Pamuk, a Nobel Prize laureate and Turkey’s most prominent living intellectual?

To treat its minorities better, Turkey should begin by acknowledging its historical sins against them. It should begin with the Armenians, and then apologize for its genocides of Assyrians and Greeks in the final days of the Ottoman Empire.