( JTA ) — More than four months into its devastating war against Russia, Ukraine is sending a new message to the world’s Jews: Don’t come here for Rosh Hashanah. Tens of thousands of Jews flood into Uman, a central city that is home to the grave of Rabbi Nachman of Breslov , a 18th-century Jewish luminary, annually for the Jewish new year. Even in the first year of the pandemic, when global travel ground to a halt and the gathering was officially banned , Jewish pilgrims sought to make their way to Uman. This year, their security cannot be...