To those who signed that New York Review of Books letter “For an Economic Boycott and Political Nonrecognition of the Israeli Settlements in the Occupied Territories”: I write with great respect and deep sorrow. I know many of you, and have learned a lot from even more of you. I have no desire to polemicize, demonize or ostracize, and I hope you will take my comments as an invitation to the kind of open, substantive debate about Israel (and the Palestinians, they count too here) that rarely occurs in the Jewish community – or the academic world – the two universes most of us share.I read your 196-word contribution to this complicated conflict, and was appalled by its naïveté, one-sidedness, destructiveness and unfairness – especially to Jewish and pro-Israel students.That such sophisticated thinkers, who have done so much to teach me (and many others) about politics, power, justice, history, culture, America and Judaism, could really believe your careful modifiers emphasizing that this is only a “targeted” boycott “of all goods and services from all Israeli settlements” is so preposterous it makes me doubt your sincerity. That anyone in the anti-Israel lynch mob will respect your genteel distinctions is as believable as Donald Trump when he says “believe me.” Your letter makes you enablers, dupes. To the boycott forces and the media, supporting a targeted boycott supports a boycott.Moreover, as precise writers, note the second half of your sentence: “and any investments that promote the Occupation.” Follow your words’ logic, as so many of you have taught undergraduates to do. Objective readers, let alone Bash-Israel-Firsters, could consider every investment in any part of Israel an investment that promotes the occupation, because money and support are fungible.Even without your legitimizing shunning every Israeli, the boycott movement, fueled as it is by an irrational hatred of Israel and Jews, is no more contained than any other gang of bigots. Your slope is slippery – and you cannot claim you haven’t seen it before against Jews and other targeted groups. Boycotts, like bigots, metastasize – first goods, then people. You start by boycotting West Bank goods, then “settlers,” then Israeli goods, then Israeli citizens, and then Jews. (And remember, most Palestinian radicals call all Israelis “settlers” and consider all of Israel occupied).Similarly naïve is your refusal to denounce the anti-Semitism that follows the boycott movement like carbon monoxide follows smoke. At my own university, McGill, last year’s Boycott, Divestment and Sanctions (BDS) debate proved, as in other universities, that BDS unleashes bullying, demonization and slander. Simon Paranski, a law student, told CTV that “within an hour of the BDS vote passing, there were posts on social media about Zionist Jew-boys and insulting people of the Jewish faith.” One tweet sneered: “Little Zionist Jewboys not happy that McGill students don’t support their genocide.”Jewish students also reported being menaced. Moreover, last week, Jewish students told me that the feminist, LGBT and Black Lives Matter clubs at McGill were clear: if they wanted to be involved in those social justice movements, they had to – to hijack Peter Beinart’s wording – check their Zionism at the door.This is the last Trump card I’ll play. I – and I’m guessing most of you – blame Donald Trump for not taking responsibility and denouncing his allies’ hooliganism and bigotry.I hold you to that same standard.You should write a second letter, paralleling the one I and over 150 McGill professors signed, saying: “We all need to affirm our commitment to fighting bigotry of all kinds, even when masked behind human rights rhetoric or even if allied with political positions we might support. We fail when our students don’t feel genuinely safe in our university – and the BDS movement has made McGill students feel unsafe, unsupported and unwelcome in their and our academic home.”Your naïve letter is also counterproductive. You claim you want “to promote... negotiations.” Yet the more Israel is delegitimized, the more unreasonably Palestinians act and the less compromising Israelis feel. The more Left you are, the more you seek sweeping territorial concessions from Israel, the more ardently you should fight boycotts, Israel-bashing, anti-Zionism and antisemitism.Note, Israelis respond to love love, not tough love.When the UN in 1991 renounced its Zionism is racism resolution, and when Bill Clinton emerged as Israel’s cheerleader in chief, Oslo and other compromises followed.And when the UN passed the Zionism is racism resolution in 1975 and 26 years later resurrected that libel at Durban, waves of terrorism bolstering Palestinian rejectionism followed. Finally, let’s face it, Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas don’t care about your words or my quibbles. But as academics and intellectuals your words count on campuses, where many of you are revered. That’s why I accuse you of being unfair to Jewish and pro-Israel students on those campuses facing boycott threats. They needed a more sophisticated, balanced, multi-dimensional letter. And they needed – and still need – a clear, eloquent, denunciation from you of the “kosher” antisemitism and anti-Zionism – perfumed by social justice talk – haunting too many campuses and spreading on the Left.In that fight, the more outspokenly critical of Israel you are, the more credibility you have – although you will see that the Israel haters, like all irrational bigots, pick and choose. They will happily quote and misquote your harmful letter – ignoring any denunciations of the hatred they have unleashed on some campuses, including my own.The author is a professor of history at McGill University, is the author of The Age of Clinton: America in the 1990s, published by St. Martin’s Press. His next book will update Arthur Hertzberg’s The Zionist Idea. Follow on Twitter @ GilTroy.