He is an activist for Israeli-Palestinian peace, the sort of person who, in recent years, volunteered to drive chronically ill patients from Gaza to specialized care in Israeli hospitals. In March, he wrote a blog post praising Jewish and Arab Israeli students who, together, shipped earthquake relief to Turkey.

And Peri was an esteemed leader of his community, Kibbutz Nir Oz — Hebrew for “meadow of strength” — when, on Oct. 7, some 200 Hamas terrorists attacked, leaving it a smashed-up, smoldering ruin.

Out of approximately 400 Nir Oz residents, Hamas killed 27 and took 73 to Gaza as hostages. Sixteen captives are children, the youngest being 9 months old, and 25 of them are older than 75 — Chaim Peri among them.

I learned about this remarkable man, and his terrible predicament, from Noam Peri, 40, his daughter. She visited Washington this week to raise support for the cause of all of Hamas’s 220 hostages, but especially those from Nir Oz, who make up about one-third of the total.

Noam Peri told me she is lobbying U.S. officials “for specific pressure” on Hamas leaders who are abroad and on the countries — Qatar and Turkey — that host them. The goal should be “to make them uncomfortable to live their life while my father and my friends are kept in tunnels in Gaza.” It’s an appeal that the Biden administration has met, to some extent, by imposing economic sanctions on certain Hamas operatives and the group’s financial network.

Yet the administration hesitates to isolate Qatar, the Persian Gulf state that supplies the United States’ European allies with energy and hosts a U.S. military installation and whose diplomatic contacts with Hamas the United States is counting on to help negotiate freedom for the captives. Israel’s own national security adviser offered unusual praise for Qatar’s role Wednesday.

Noam Peri said her main point is that the release of all of them has to be a “clear priority” for the United States, Qatar and her own country’s prime minister. A possible starting point, she observed, could be “clear humanitarian cases, such as children and the elderly.” She and other hostage families worry, understandably, that global attention on the hostages will fade as other considerations — the humanitarian crisis in Gaza, regional military strategizing — take up political bandwidth.

The release on Monday of two elderly Jewish women who had been held hostage in Gaza buoyed Noam Peri. One of those freed was from Nir Oz; she had seen Chaim Peri during her underground captivity and reported that he was still alive. A former Israeli Mossad hostage negotiator, David Meidan has suggested publicly that Hamas might trade for the release of its very young and very old hostages soon, if only because it takes “extra logistics” to look after them. Such are the scraps of hope hostage families cling to.

Assaulting Nir Oz and four other nearby kibbutzim, Hamas was attacking strongholds of liberal Israel, whose residents probably could be seen recently taking to the streets in protest of Prime Minister Benjamin Netanyahu’s right-wing government. That irony, so poignantly encapsulated in the terrorists’ capture of her father, is not lost on Noam Peri; she notes, however, that it doesn’t change the fact his kidnapping is “a crime against humanity.”

“My father is a peace activist,” she told me. “He believes in human rights, but he is not naive. He never thought Hamas wants anything other than hurting and killing the Jews. He knows that Hamas is not good for Palestinian rights. Hamas … also holds the Gaza people hostage.”

Perhaps, in some complicated way, Chaim Peri’s plight can help his brand of moral clarity gain traction. To be sure, decent people around the world share his assessment. However, too many self-styled progressives in the United States and elsewhere have suggested that what Hamas did in Nir Oz somehow qualifies as “resistance” to Zionism or settler colonialism.

Noam Peri has a message for them, too: “What Hamas did in Nir Oz and in other places has nothing to do with resistance. It’s an act of genocide. We haven’t seen this or heard these stories since the Holocaust.”