The day Afghanistan's non-Muslims have to start wearing a distinctive marker, I'll put one on too. But I won't claim any special credit for this small show of support for religious minorities who, by recent decree of the Taliban, are to be visually set aside from neighbors they've lived among for centuries.

To be worthy of an ethical merit badge, such a gesture should be the result of having weighed alternate courses, wrestled with potential consequences, made choices. But my pledge of solidarity with Afghanistan's tiny Hindu community is a direct deduction from something I know.

It is no more a matter for soul searching than is, say, the question of how much 5 plus 5 makes.

For me, the determinative fact is this: On June 7, 1942, the non-Jewish students of a public school in Paris, Ecole rue Michel Bizot, showed up for classes wearing yellow Stars of David.

That badge was the Nazis' cruel parody of a venerable symbol. Known as the Magen David, the Shield of David, that set of superimposed triangles forming a star was a proud reminder to Jews of the most powerful king of ancient Israel. Hitler turned it into a sign of powerlessness.

Upon coming to power in Germany, he decreed that Jewish businesses had to be marked with a Star of David. Eventually, the country's Jews had to display one on their clothing too. Theirs had to be yellow, a color associated with cowardice and deceit. Requiring it to be worn was a key element in a campaign to turn the country's Jews into pariahs.

To that point, Jews weren't particularly distinguishable on the streets of Berlin and other German cities. Unlike the more traditional Jews of Eastern Europe, they didn't wear long black coats and old-fashioned-looking fur hats. Germany's Jews had opted for modernism. They were assimilated into the larger society. Many had served with valor in the German army during World War I.

All that was changed by those mandatory yellow Stars of David. Day in and day out, they told gentile Germans which of their neighbors and friends they now had to hate. The sight of those stars on armbands and in shop windows helped inflame murderous passions that enabled ordinary Germans - the epitome of a civilized people, a people famed for the genius of Beethoven and Goethe - to serve in SS death squads and to run the gas chambers of Auschwitz and Treblinka.

Whoever the Nazi armies conquered during World War II, the yellow star was imposed on local Jewish communities. For millions, it was a first step on the way to a concentration camp. In the spring of 1942, when the young people of that Parisian school put on yellow stars, the time had come for France's Jews to begin that deadly journey.

The non-Jewish students of the Ecole rue Michel Bizot are said to have thought that their wearing of the yellow star would make it harder for the Nazis to single out their Jewish classmates. Probably things didn't work out that way. The German authorities knew where Jewish families lived, having taken a special census of France's Jews. By the summer of that year, thousands had been rounded up and packed into a Parisian sports stadium, from which they were deported to the death camps.

But whether or not the brave act of defiance saved any lives, those young French students provided subsequent generations with a question worth pondering in similar circumstances: When people are being singled out because of the superficial differences that distinguish one group from another, aren't decent folk obligated to publicly proclaim that they recognize the essential unity of the human race?

The Taliban and their supporters abroad say the question isn't applicable there. Afghanistan's religious authorities explain that non-Muslims will wear a distinctive badge for their own good. That way, the country's religious police wouldn't punish them for not observing the strict regulations of dress and practice to which Muslims are held.

But the record of history clearly says to beware such explanations for prejudice. Whenever discrimination has been explained as being good for those discriminated against, much worse things have generally followed.

When the Jews of medieval Europe were confined to walled ghettos, local authorities often said it was done only to protect them from being attacked by Christians. When the 13th-century Pope Innocent III ordered that not only Jews but Muslims also had to wear distinctive clothing, he claimed he was only helping them enforce tenets of their own religion requiring them to do so.

Under the Nazi regime, Jews often were ordered to pack their belongings and report to a local railroad station. They weren't told that crematoriums awaited them at the end of their journey, but that they were being taken to new settlements of their own. There, the German authorities cynically promised, Jews would be protected from anti-Semitism.

Though I hope and pray it turns out differently for the non-Muslims of Afghanistan, I fear that enforced discrimination in dress will be, once again, only the first step toward further isolating them from their fellow citizens. So I feel obliged to follow to lead of those French students by making a visual statement of solidarity with Afghanistan's minorities, though I wouldn't presume to tell others to do so.

Yet I do note that we have just come through the Jewish holiday of Shavuot, which commemorates Moses receiving God's commandments on Mount Sinai. Jews have long marked the occasion by staying up the whole first night to study religious and ethical questions. Tradition has it that we do so because, when Moses came down from the mountain, he found no one awake to welcome him and the divine revelation he bore.

Our ancestors were sleeping in that morning.

Unfortunately, there could be no better metaphor for too much of recent history. Since the dawn of the 20th century, good and decent people have too often slept in, even as evil was being done to others.

Between 1915 and 1919, more than 1.5 million Armenians died as Turkish authorities tried to eliminate that ancient people from its ancestral homeland through deportations and forced marches. It is said that the Nazis took heart that they would get away with their atrocities because of how little the rest of the world had done to protest the Armenian genocide.

More recently, notice how slow other nations have been to respond as, in the Balkans and in African countries, people were being killed simply because they spoke a different language or worshiped differently than their neighbors.

Of course, the impulse for bystanders to look away, to say, "It's not my battle," is an all-too-human response. The problem is that, each time we do so, the pool is reduced of those available to protest when our time of trial comes. Of that fact we were forewarned by Pastor Martin Niemoller, a German clergyman who felt obliged to protest the Hitler regime, even as others thought it prudent to keep silent. He went from one concentration camp to another, until the end of World War II.

"In Germany, they first came for the Communists," Niemoller said, "and I did not speak up because I was not a Communist. Then they came for the Jews, and I didn't speak up because I wasn't a Jew. Then they came for the trade unionists, and I did not speak up because I was not a trade unionist. Then they came for the Catholics, and I didn't speak up because I was a Protestant. Then they came for me - and by that time no one was left to speak up."