At first, it looked like a confrontation might unfold, as has happened several times at volatile street protests in New York over the past six months. As students chanted “Free Gaza,” Zach yelled “from Hamas,” referring to the Palestinian terrorist group that runs the enclave and launched the Oct. 7 attacks that triggered Israel’s invasion of Gaza. Protesters started jeering and yelling. One called him a Nazi. Zach, a 23-year-old Israeli who owns a clothing brand, happened to be walking Tuesday near Washington Square Park, the site of a protest by New York University students against Israel and the war...