Right now in Japan there is total chaos while the authorities try to manage the broken infrastructure. Having hundreds and hundreds of people trying to get to the ravaged zone all at once is silly. This proved itself in the Haiti situation. Waiting one more day for Shabbat to end is not going to make matters worse. Japan is a modern country with enough people to get started on the rescue mission.
Law expanding definition of terrorist activity passes first Knesset reading (Haaretz)