In the last question, I asked "who-did-the-jews-fight-on-purim-if-nobody-could-oppose-them".
On the second thought, the Amalekites are known with their natural hatred for the Jews, as they came to fight the Jews after the Exodus, when the Jews were in their highest (Exodus 17.8).
But on Purim they suddenly got scared (Ester 9.5):
...וְאִישׁ לֹא־עָמַד לִפְנֵיהֶם כִּי־נָפַל פַּחְדָּם עַל־כָּל־הָעַמִּים׃
...the Jews mustered in their cities to attack those who sought their hurt; and no one could resist them, for the fear of them had fallen upon all the peoples.
So I wonder, why those Amalekites feared the Jews such that they didn't fight the Jews back when allowed by the first decrees even if they knew they are going to lose?