Military targets yes, if there is a missile launcher or ammo in an israeli building, yes it is a valid target. You have to right to kill anyone who’s actively trying kill you.
Israel definitely could have avoided this, and not fuck up the whole situation so much, but it’s not a simple matter… and self defense is a simple matter… if someone shoots at you, you kill them. That’s what happens when you take a gun. If you massacre a bunch of civilians, then people are going to shoot at you and your accomplices with passion
The deliberate targeting of civilians is horrible. But it’s well documented that hamas uses people as meat shields, by using civilian buildings as ammo depots and rocket launching platforms. That’s, unfortunately, a fair target then…