It's always blame someone else. Blame Hamas. Blame Islam. Blame Antisemites. If there was no wall, and every Palestinians was a full Israel citizen there would be no Hamas. But there is a wall because Israel wants to remain a Jewish-first State. It's a tradeoff that must be managed well or you get an insurrection. This is true for every place where an ethnic minority creates two sets of rules.

Justification to who? To yourself? To God? To non-Jews? Israel went its own way. The rest of the world will go theirs. Anyway, you don't need to justify yourself to me! I have my own sickos in government to worry about ;)