Tisha B’Av, the fast day that commemorates the destruction of the Temple in 70 CE, comes this year at a particularly fraught moment for the Jewish people. The only surviving architectural element of the Temple, its western restraining wall, has become a site of contention both between different religious movements and between world Jewry and the Israeli government. At such moments, there is a strong temptation to appeal, as the U.S. ambassador to Israel recently did, to the idea of Jewish unity—“that nobody ever has to win” if we all work together and respect one another.