Consider:
The edict of Achashverosh cannot be revoked, so the Persians are still allowed to destroy the Jews. Mordechai writes a new edict allowing the Jews to fight back. Should there be limits on how the Jews can fight back or what they can do?
(1) Now in the twelfth month, which is the month Adar, on the thirteenth day of the same, when the king’s commandment and his decree drew near to be put in execution, in the day that the enemies of the Jews hoped to have rule over them; whereas it was turned to the contrary, that the Jews had rule over them that hated them; (2) the Jews gathered themselves together in their cities throughout all the provinces of the king Ahasuerus, to lay hand on such as sought their hurt; and no man could withstand them; for the fear of them was fallen upon all the peoples.
(א) אֵין הַמֶּלֶךְ נִלְחָם תְּחִלָּה אֶלָּא מִלְחֶמֶת מִצְוָה. וְאֵי זוֹ הִיא מִלְחֶמֶת מִצְוָה זוֹ מִלְחֶמֶת שִׁבְעָה עֲמָמִים. וּמִלְחֶמֶת עֲמָלֵק. וְעֶזְרַת יִשְׂרָאֵל מִיַּד צָר שֶׁבָּא עֲלֵיהֶם. וְאַחַר כָּךְ נִלְחָם בְּמִלְחֶמֶת הָרְשׁוּת וְהִיא הַמִּלְחָמָה שֶׁנִּלְחָם עִם שְׁאָר הָעַמִּים כְּדֵי לְהַרְחִיב גְּבוּל יִשְׂרָאֵל וּלְהַרְבּוֹת בִּגְדֻלָּתוֹ וְשִׁמְעוֹ:
(1) A priori, the king does not go to fight other than a War of Mitzvah (Mandatory War). What is a War of Mitzvah? This is the war against the Seven Nations or the war against Amalek or any war to assuage Israel of a persecutor. After this, he may fight Discretionary Wars which are those wars he conducts against the other nations in order to enlarge the borders of Israel, and increase his renown and reputation.
Consider:
Why does our tradition link Haman and the nation of Amalek?
יְמִינִי — דְּלָא קַטְלֵיהּ שָׁאוּל לַאֲגָג, דְּאִתְיְלִיד מִינֵּיהּ הָמָן דִּמְצַעַר לְיִשְׂרָאֵל.
Benjamite — Saul, who was from the tribe of Benjamin, did not kill the Amalekite king Agag immediately, from whom Haman was later born, and he caused suffering to the Jewish people.
Consider:
Why is Mordechai linked to Amalek (through the genealogy of Saul)? What is the Talmud implying that Mordechai learned from his ancestor?
Why did the people of Persia fear the Jews? Do you think that was Mordechai's intent? Why or why not?
The Dawn: Political Teachings of the Book of Esther by Yoram Hazony
By the opening of the actual war, it was clear to all that the influence of the Jews in the empire had become overwhelming. The hard core of anti-Semitic power had been isolated, as "All the princes of the provinces, and the satraps, and the governors and those that conduct the kind's affairs supported the Jews."... Presumably, Mordechai now had the option of restraining the fury of the promised Jewish onslaught. There was no longer much question of a real anti-Semitic assault... [But] throughout the empire, the Jews enter into battle with the anti-Semitic forces, in most cases with the active assistance of the allies who have rallied to support Mordechai's position. Abandoned by most of their former supporters in the populace and in the government, the anti-Semitic inciters and those who had actively advanced their cause are brought low in province after province. The carnage is so great that (i) the anti-Semitic basilisk is in fact beheaded, its life and leadership burned out of the body politic, and (ii) the lesson is learned by all future challengers to the safety of the Jews and the power of Mordechai in the king's court. Nowhere in all the vast reaches of the Persian empire does there any longer exist a leader capable of inspiring the peoples to rise and harm the Jewish communities, nor can anyone imagine becoming such a one while Mordechai's influence persists.
וַיַּכּ֤וּ הַיְּהוּדִים֙ בְּכָל־אֹ֣יְבֵיהֶ֔ם....וַיַּֽעֲשׂ֥וּ בְשֹׂנְאֵיהֶ֖ם כִּרְצוֹנָֽם. הנה ודאי לא היה הרשות נתונה ליהודים להרוג את כל מי שירצו, כי לא היה כתוב בהספרים רק להנקם מצורריהם, ואחר כי עתה איש לא עמד בפניהם בהכרכים הגדולים, לא היו הורגים רק האויבים שאיבתם אל היהודים היה מפורסם שהיו מגזימים להרע להם, אבל לא את השונאים (כי ההבדל בין אויב ושונא שהאויב איבתו גלויה, והשונא אין שנאתו גלויה) רק ויעשו בשונאיהם כרצונם, שהיו יכולים לגנות אותם ולהשפילם:
And the Jews struck at their enemies... and wreaked their will upon their haters. It is certain that permission was not given to the Jews to kill whomever they wanted, because it was only written in the letters that they were to get revenge on their enemies. And after, because "no one could withstand them" under great duress, they only killed their enemies (oyevim)—those whose loathing for the Jews was famous and who spoke extensively of harming them—but not their haters (son'im) (because the difference between an enemy and a hater is that the enemy has open loathing, but a hater's hatred is not in the open). With the haters, they only "wreaked their will," that they were able to denigrate and humble them.
הרגו היהודים ואבד. לשון ואבד קשה קצת דאיזה איבוד שייך אחר הריגה. ונראה שכוונתם הי' להרוג כל משפחה ומשפחה שלא ישאר שום גואל הדם ושיתאבד זכר ההרוגים משושן וכל הריגתם היה רק בהעמלקים וכיון שמצוה למחות זכר עמלק ואסתר ראתה שעדיין נשאר הרבה מהעמלקים בשושן מה שלא הספיקו להרוג את כולם ביום אחד לכך בקשה שינתן בשושן עוד יום אחד:
"The Jews have killed and destroyed"—The word "and destroyed" is a bit challenging, because what destruction can there be after killing? It seems that the intention was to kill every family, so there should be no avenging party left, and the memory of those killed would be entirely gone from Shushan. And all of this killing was only of Amalekites, and because there is a commandment to wipe out the memory of Amalek, and Esther saw that were were still many Amalekites in Shushan that [the Jews] had not yet managed to kill on the one day, and that is the reason that she asked for an additional day [of fighting] in Shushan.
Why does the tradition try to mitigate the violence of the culmination of the Purim narrative? Do you think that this aligns with the exhortation to exterminate Amalek?