the outbreak of world war ii caught him during his visit in the british mandate of palestine, after which he was intending to visit united states. learning about red army occupation of lithuania, he decided to stay in palestine. he continued overseeing panevezh yeshiva from distance. after the entrance of nazis to ponevezh the yeshiva was destroyed and all students murdered. a few years later, in 1944, kahaneman succeeded in re-establishing ponevezh yeshiva in bnei brak. after un-successful attempts to save european jews, kahaneman focused on developing communities in palestine and built "kiryat ha-yeshiva" ("town of the yeshiva") in bnei brak and "batei avot" orphanages. he also traveled widely in the diaspora to secure financial support for the yeshiva, which he constantly improved and extended. with the help of long time friend rav moshe okun, kahaneman succeeded in turning the re-established ponevezh yeshiva into one of the largest in the world and leading among the litvishe.