Last Shabbat, I was enjoying a great Jewish peoplehood moment. Praying in an Eilat hotel, I loved the easy mixing between Ashkenazi and Sephardi Jews, the proficiency of many non-Orthodox but deeply traditional Sephardim, and that one guy, at every hotel, who takes charge and organizes the prayers. Then, I started contemplating last week’s events, the freshly dug Israeli graves, the heartbroken families enduring the worst Shabbat of their lives. I also thought about two of Israel’s latest heroes, also experiencing the worst Shabbat of their lives – the Border Policewomen who stopped the Jaffa Gate stabbings but mistakenly shot a passerby who intervened, Ofer Ben-Ari.When two Palestinian terrorists started slashing pedestrians, including Rabbi Reuben Birmajer, a 45-year-old Argentinian immigrant and father of seven, Ben-Ari, the 46-yearold father of two, rushed from his car to help, despite being unarmed. Two border policewomen reacted, as they were trained to do, shooting the terrorists but also killing Ben-Ari amid the mayhem. Predictably, CBS reported, perversely, “2 Palestinians killed after stabbing attack in Jerusalem.”Presumably, forensics determined which officer killed Ben-Ari. But both those heroines deserve medals. They did what we needed them to do: stop the slashing. They should be reassured in a personal visit by the chief of staff, the defense minister, or the prime minister that they reacted properly and the state supports them.They – and all our young soldiers and first responders – must know that we trust them to trust their training and their instincts, knowing that, sometimes, things go wrong. We need soldiers disciplined enough not to panic and fire irresponsibly but bold enough not to second-guess so much that they or others get killed.In all wars, soldiers are killed by friendly fire, errant bullets. An Israeli sentry shot one of Israel’s first war heroes, the American colonel Mickey Marcus. In 1991, friendly fire killed as many as 20 percent of the Americans who died in the First Gulf War. Such is the chaos of war. These young border patrollers and their peers must know that they we don’t blame them for Ben-Ari’s death.The police are not to blame because the Palestinian slashers are guilty. And the police are not to blame because Palestinian Authority President Mahmoud Abbas and his Palestinian political culture of incitement are also guilty for riling up the killers. Abbas’s latest outrage, Palestinian Media Watch reports, is proclaiming: “We said to everyone that we want peaceful popular uprising, and that’s what this is.”Abbas lies and inflames so regularly he makes Donald Trump look truthful, precise and composed. We are so accustomed to Abbas’s Big Lies, his demonizing Israel, his Orwellian twisting of stabbings, shootings and car rammings into a “peaceful popular uprising,” that we rarely respond. US President Barack Obama also remains silent amid this lethal incitement, maintaining the fiction that Abbas is the Palestinian moderate.IN TRUTH, when I think about these young women, I feel guilty too. I watch these youngsters defending us, I see my kids and their friends stepping into the line of fire, and I wonder if we middle-agers should be doing our society’s dirty work instead of them. We failed to give them the peaceful world they deserve. We deputize them to make impossible, split-second, life-and-death decisions, when they should be focusing on which courses to take and which hottie to date. And we have the life experience and steadiness to cope emotionally with the traumas this situation imposes on our defenders daily, whether they fire or not, whether they “neutralize” a terrorist or mistakenly, tragically, kill an innocent hero.When I look at these young heroes, I feel guilty but proud. Alas, some other Israelis make me feel guilty and ashamed. I am embarrassed to share the planet, let alone my state, religion and national identity, with degenerates who murder members of an Arab family in Duma or celebrate such evil in the now-infamous wedding video. I am ashamed of their rabbis who mock Jewish law, including that top-10 one against murder and the many injunctions to respect the stranger. And I am ashamed of the many passive head-nodders, who are not as crass as the revelers dancing wildly with guns and pictures of dead Arabs, but tolerate such violence.Palestinian terrorists don’t need Israeli extremists to target Jews – and Palestinian hate ideology long predated these marginal nutbars. But our extremists are an unnecessary gift to our enemies, adding more sparks to an already incendiary situation.Still, I note proudly that most Israelis, from Left to Right, denounced these thugs, including Israel’s supposedly right-wing, fanatic leaders. A visitor this week, a recent Princeton graduate, Harry Cape, notes that the best way to fight terrorism is for each community to learn the concept of a “shanda,” Yiddish for shame or scandal.Understandably, Zionists have long bristled at the term. For millennia, Jews were hyper-worried about looking bad in front of others – and took the resulting self-blame too far, although Jews learned to self-police effectively.Now, with a Jewish state, Jewish power, and Jewish deviants within that state, we need some self-blame and self-policing.If more Palestinians – and Muslims worldwide – believed that Islamists terrorism was a shanda, they would do what Israel is doing – not just condemning these criminals but arresting them. Instead, of course, too many Palestinians, and yes, too many Muslims, applaud the terrorists, neutralizing the most effective counters – self-blame and self-policing.Israel isn’t perfect. But I ended my Shabbat reverie proud of self-sacrificing heroes like Ofer Ben-Ari, the two police officers and their peers working overtime; proud of our self-critical leaders; and proud of our Zionist democratic culture, that takes responsibility for strangers when endangered – and for strange Israelis who endanger others.The writer is the author of The Age of Clinton: America in the 1990s, just published by Thomas Dunne Books of St. Martin’s Press. He is professor of history at McGill University.Follow on Twitter @GilTroy www.giltroy.com.