In game theory there is a game called the Prisoner's Dilemma. There are many strategies; ignoring details, the second most successful strategy is Eye-for-an-Eye, that is, you are nice if your opponent is nice, and you take revenge if your opponent betrays you.
The problem with this strategy is that two opponents can get locked into an endless cycle of revenge. This is the worst possible outcome of the game. It's just like the saying attributed to Gandhi: "An eye for an eye leaves the whole world blind." That's a very curious phenomenon: the second-best strategy, which leads to better outcomes almost all the time, sometimes leads to an outcome that is worse than all the other strategies. It would be better to make decisions at random, or always be nice, than to get trapped in this worst possible outcome.
So what is the best strategy? The best strategy is a slight modification of Eye-for-an-Eye. It's called Eye-for-an-Eye plus Forgiveness. In this strategy, if you become locked in a cycle of revenge, you occasionally stop taking revenge. This makes it possible to break the cycle. The cost is you miss a few chances to take revenge: your opponent hit you a few times, but you didn't hit back. But this cost is far outweighed by the benefit, which is that you can avoid what is by far the worst possible outcome.
Both sides MUST be willing to suspend retaliation. It is in the interest of both sides to do this. And when one side suspends retaliation we MUST get the other side to reciprocate or yet another chance for peace is missed. Even if you favor Israel, or Palestine, you must agree with this, because it is in their own interest. And that is not even to mention the ethical reasons for opposing violence.