It actually is possible to support Israel's right to retaliate against Hamas, and to also support innocent civilians in Gaza & things like humanitarian aid to Gaza.
This wouldn't have been as much of a thing a few decades back. We used to allow for more nuanced discussion. Now, everything is black & white. You're either on this side, or that side.
Remember this from history class?

Was it right to drop that bomb on Japan's two well populated cities?