In November, a bilingual Arabic and Hebrew school in Jerusalem was set on fire and vandalized by a group of right-wing hard-liners. The arsonists scrawled slogans such as “Death to Arabs,” “You can’t coexist with cancer,” and “Enough with assimilation” on the walls of a classroom in the school, which strives to set an example for Israeli-Palestinian coexistence. In the weeks that followed, Israeli authorities detained 21 suspects connected to the Lehava extremist group on charges of incitement to hatred. Three youths, two 18-year-olds and a 20-year-old, have been charged with carrying out the act. Now, after remarks by Israeli...