It's not a yes or no question, because national politics is not a zero sum game. Israel's actions are justified based on what Israel values - namely itself. The people who formed Israel have to survive a hostile world that repeatedly tries to destroy them.
In response they are taking actions that are certainly not justified from an outside point of view. They steal land and harm the indigenous population. The Palestinians certainly did not deserve what Israel has done, and so in that way it is not justified.
Ask yourself this. If you and you family are trapped on an island with another family and there is only enough water for one family -- would your actions be justified? That is the reality for Israelis, or at least it is the reality they see.