Israel is withdrawing some forces from Gaza to shift to more targeted operations against Hamas, and is partially returning reservists to civilian life to help the economy as the war looks set to last well into the new year, an Israeli official said. The official said toppling the Islamist faction remained an objective of the offensive in the Palestinian enclave, and that some of the five brigades withdrawn will prepare for a possible flare-up of a second front against Hezbollah in Lebanon.