Display boards in the German city of Kassel advertising tickets for the 15th Documenta art festival in 2022. Photo: Reuters/DPA One of the world’s leading festivals of modern art was embroiled in a row over antisemitism on Monday, linked to the participation of organizations that advocate for a comprehensive boycott of Israel. The supervisory board of the Documenta festival — a three-month long art event that begins in June in the German city of Kassel — was examining allegations from a local activist group, the Kassel Alliance Against Antisemitism, that two of the participating organizations actively support subjecting Israel to...