After a near-war between Israel and Hamas in Gaza, there’s now a “cease-fire” in place. But underneath, feelings are boiling; feelings that themselves can be the seeds of future conflict. Those feelings are very similar to feelings in America after the 9/11 attacks. At that time, I wrote a 20-page piece on what our reactions might reasonably be. I never finished it, but I found parts of it very pertinent to what’s being said and felt in the Jewish and Israeli community now. I urge that we think not only of how we feel now — so soon after the hundreds of rockets that were fired at civilian populations in Israel — but ask ourselves: What kind of world do we want to build with our feelings? What kind of world do we want the people of Gaza to build? I pose the same questions to the Gazans. The following is excerpted from that paper on 9/11.
We must ask ourselves gently, patiently, and with regard for our own feelings and the feelings of others, which reaction – among the entire range of reactions open to us – is going to be the most useful, the most productive, the most helpful — to ourselves, our family, our friends; to our country; to our whole world?
Is it reasonable to ask people to love terrorists? No — not without a deep, prolonged spiritual preparation to do so. But even if we can’t love those who harm us, we should remember that by hating them, we cooperate with them in harming ourselves. It’s “reasonable” to ask people to choose, from the various reactions they can have, the one (or ones) that will be the most beneficial (even relatively) to themselves.
With that consideration in mind, we do not want to hate, because of the negative effects our hatred would have, not only on ourselves, but also on the world.
The terrible acts of “9/11” (and the more recent ceaseless bombing of the civilian population in Israel) were committed by people no less human than we are, who lowered themselves immeasurably by denying to themselves that our humanity is equal to theirs. The more they devalued our lives, the more they devalued their own. Such smoldering, ignorant hatred can, in the end, do nothing other than explode and destroy the haters along with those they hate. We must guard ourselves with utter vigilance against doing the same.
With what attitude should we “fight?” We shouldn’t fight to destroy people; we should fight, if we must, to preserve life. Our prayer should be, “Let sins, not sinners, cease.”
“There were some lawless men living in the neighborhood of Rabbi Me’ir, and they used to vex him sorely. Once, Rabbi Me’ir prayed that they should die … Beruria [his wife] exclaimed, “… pray that they repent and be wicked no more…” 
Should we rejoice at the destruction of those who harm us? Torah says “No”:
“The angels wanted to sing a song at the destruction of the Egyptians at the Red Sea, but G-d said, ‘My children lie drowned, and you would sing?” 
The Midrash’s intention is startlingly obvious: Even those who hate us and would harm or even destroy us, are G-d’s children, too. That doesn’t excuse what they do (the Egyptian soldiers were drowned, after all). Rather, it tells us that the destruction of any human being — even when “justice” or “karma” require it — is sorrowful to G-d and should therefore be sorrowful to us.
After 9/11, Rabbi Levi Yitzchok Horowitz — the “Bostoner Rebbe” — said the following:
“…it is essential to focus on the concept that good is more powerful than evil; that each of us has a greater power to build, and to heal…than those who might succeed in destroying and killing. And we exercise our power of good through our acts of kindness, not only towards our fellow Jews, but also to all peoples of the world. These acts of kindness represent walking in the ways of God…Our Sages, of blessed memory, tell us that the force for good is 500 times stronger than the power of evil. If evil by the hands of a few people can create so much suffering, pain and devastation, just think how much more opportunity there is for the multitude to do good, to move in the opposite direction from evil: comforting, healing, and building. Each and every one of us possesses such a great potential for good to contribute to civilization and the world. This is a powerful message. We are therefore the bearers…of an action plan to build a better world. Our inadequate feelings and emotions have to be put aside at times, in order to direct our energies to creating a better world through building a better community, a better family, a better self, through attaching ourselves to our Creator.” 
Doing so, we invoke G-d’s help in the highest way possible, as it says in “Mishlé” (“Proverbs”):
“When a man’s ways are pleasing to G-d, He makes even his enemies to be at peace with him.” 
Let’s ask ourselves:
“What good can we do?”
“What can we do to please G-d?”
“How can we harmonize ourselves with that Divine Presence in ourselves that we share with all Creation?”