The lesson is clear: Jews, with their history, cannot become the systematic oppressors of another people. They must be vociferous in their insistence that continued colonization of Palestinians in the West Bank will increase Israel’s isolation and ultimately its vulnerability.Cohen seems to saying here that the way to get rid of some forms of antisemitism in western countries is to oppose the settlements, and the Israeli occupation, in the West Bank. Does Roger really think that opposing the settlements in the West Bank is a way to get rid of antisemitism in western countries? He's ascribing a rationality to antisemitism that simply isn't there. If Israel didn't have settlements in the West Bank, I suspect antisemites would find plenty of other reasons to hate Jews.
That — not fanning Islamophobia — is the task before diaspora Jews. To speak up in Britain also means confronting the lingering, voice-lowering anti-Semitism.
I also oppose the settlements (most of them) as an obstacle to peace, but I don't say so with the goal of opposing antisemitism, or for that matter opposing anti-Muslim prejudice. It's something worth doing for its own sake, rather than worrying about what antisemites think - for the sake of the future of Israel.
In my opinion, the way to oppose antisemitism is simply to speak out against it forthrightly whenever it appears in any of its forms: if it's the supposedly genteel antisemitism that he's writing about in Britain, to call it out and say it's not funny. (And how genteel is it in fact? Such genteel antisemitism existed before WWII - was it a contributing factor in the lack of sufficient welcome to Jewish refugees from Hitler, and the White Paper that cut off Jewish immigration to Palestine?). It seems to me that the anti-Zionist antisemitism that has taken up residence among some of the British intellectuals (see the UCU - University and College Union and its attempts to forward the academic boycott of Israel) needs to be opposed by forthrightly calling it what it is, and refusing to back down in the face of the pathetic attempts to deny that it's antisemitic.