What is the Torah's approach to the killing of thousands of Hamas terrorists & especially their leaders who are being killed by Tzahal & the Mossad? Are we any different than the Azzans who distribute candy after terrorist attacks? I davka remember learning that Hashem told the angels not to sing when the Egyptians drowned in the sea!

Any semi-intelligent person knows to differentiate between celebrating the joyful killing of innocent women & babies in their beds, and retaliating to punish and deter those vicious murderers. It's true, King Shlomo said "Do not rejoice when your enemy falls" (Mishlei 24), but a few chapters before that he already stated: "There's happiness when the wicked are vanished"! (ibid, 11). The Gemara itself asks about this apparent contradiction (Megillah 16a), and answers through the differentiation: to be sad over the fall of a fellow Jew with whom you are in an argument (that you are not allowed to rejoice), but regarding wicked gentiles who hate & kill Jews, we are not only allowed, but should even be happy when they fall. As Shlomo's father David HaMelech wrote (Tehilim 58) "Let the righteous rejoice, for he has seen the vengeance of his people...". In general, anyone who has learned in yeshiva or midrasha knows that it's always important to see quotes "inside", in their context, including the source that you quoted. Chazal specify that Hashem said to the angels (not to the Jews!), not to sing at the Red Sea, because they were not parties to the suffering- they weren't the ones being persecuted and killed by the Egyptians (Megilla 10b). But we who were persecuted by the evil Pharaoh and his army, of course need to thank G-d for the victory. We say every morning the prayer of "Az yashir Moshe u'vnei Yisrael…", & Chizkiyahu was even punished for not singing to Hashem after his victory over Ashur (Sanhedrin 94a). If my brother is killed and daughter raped by someone, Hashem created us that it's totally normal and even healthy to feel hatred towards such Hitlers and terrorists. Ahavat Yisrael includes not only feeling love for my brothers, but getting angry and when necessary, fighting & taking vengeance to come to their rescue & subsequently, celebrate victory (that's many of our holidays!). Of course, we would prefer for our enemies to repent and also love Israel (or at least stop killing & raping us), but in the meantime, let's not be naïve. As Shlomo himself wrote, "There's a time for war, and a time for peace (Kohelet 3, 8), and let's not be childish in confusing the two. Rav Kook writes (Chazon HaTzimchonut, 19) that idealism must be sincere and not a "bluff". Be honest, and don't pretend to fool yourself or others, that you're on an unrealistic level of spirituality & morality, when you don't really feel it. Similarly he writes that morality is an extremely central ideal, but there are others, as well. For example, justice, truth and love of Israel are also Godly traits that we are meant to emulate in our "imitateo Dei", as well. In fact, Rav Kook adds that one who pretends to love foreigners (& how much more so, enemies!) with a similar love & loyalty which he has for his brothers, sons & daughters is apparently showing that doesn't really know what love is (Orot Yisrael 8, 5)! Yes, Christians believe in "resist not evil" and "turning the other cheek" to let one's enemy slap him there, as well, but Judaism clearly disagrees, believing it's immoral not to fight & deter the immoral. The war against wars is what bezH will eventually bring peace, and is actually super-moral. In short, it's natural, healthy, G-dly, a great mitzvah & occasion to thank Hashem when we succeed in killing those satanic evil who joyfully killed & raped us, just as we do in Pesach, Purim, Chanukah, Yom Yerushalayim, etc., and that's part of Ahavat Yisrael. As a matter of fact, part of our mistake and misconception which enabled the Hamas attack on Simchat Torah, was that we didn't realize their level of evil. Not being naive can prevent future tragedies. With Love of Israel, Ari Shvat (Chwat)