The death of Moshe Arens, who slipped away in his sleep today at the age of 93, stills one of the clearest voices in Zionism. He famously played a role in launching the career of another Israeli who had studied at MIT, Benjamin Netanyahu. A right-winger and three times defense minister of Israel, Arens nonetheless had an ability to embrace his ideological foes.

We didn’t know Arens well. In each of the several times we interviewed him, though, he made an impression for the shrewdness of his analysis and the quiet strength of his character. Sensing that an abandonment of Sinai would be a strategic error, Arens voted against President Carter’s Camp David Accord. He also understood the folly of the Oslo agreement.

For all of that — and for his newspaper columns that for years appeared in Haaretz — we admired Arens enormously. Yet the Arens moment on which we have found ourselves most often reflecting concerned none of the fine points of day-to-day policy. Rather, it was his appreciation of his movement’s Jewish ideological rivals in the Warsaw Ghetto during World War II.

This emerged in sharp relief with the death, in 2009 in Poland, of Mark Edelman, leader of the vestige of the General Association of Jewish Workers known as the Bund. Our editor wrote about it at the time in Tablet. In the Warsaw Ghetto, Edelman had been in the Jewish Combat Organization, know as ZOB, that, when the attack on the Ghetto got underway, arose from the underground and stunned the Nazis.

When the ZOB’s Mordechai Anielewicz was trapped and committed suicide rather than permit himself to be captured, it was Edelman who acceded to the leadership. He survived the war and spent his post-war life as a physician in Poland. He remained a socialist and a critic of Israel. When he died, his coffin was draped with the red banner of the Bund.

Yet it turns out that Arens, a partisan of the right-wing camp and a foe of the Bund, had once traveled to Poland to meet Edelman. When Edelman died, Arens wrote in Haaretz one of the loveliest tributes, even while acknowledging that Zionism and emigration to Palestine had been “anathema” to the Bund. The question is why.

“The Bund’s lofty ideals took precedence over reality,” Arens wrote in 2009. “And cruel reality put an end to the Bund.” Arens went so far as to say that “Zionism prevailed over the Bund.” That, though, “was not because most Polish Jews deemed its ideology superior, but because the human base of the Bund was exterminated, along with the rest of Polish Jewry, by the Germans during World War II.”

Arens was no socialist. He reminded his readers, though, that the Bund had won among millions of Polish Jews a “loyalty that sustained them during the war years, and gave them the courage to heroically fight the Germans along with other Jewish fighters, outnumbered and outgunned, in the Warsaw ghetto uprising.” His elegy to Edelman is one of the most affecting newspaper columns we’ve ever read.

As Arens himself is laid to rest, the question nags at us still — why did Arens make such a bow to a hero at the other end of the ideological spectrum? Certainly Arens understood that if we are not vigilant, the dream of Herzl could yet be dealt as cruel a fate as what befell the Bund. Yet he also understood how hard it is to predict whence, in the depths of combat, heroism will be revealed.