Zachor es asher osoh lecho Amalek – Remember what Amalek did to you (Devorim 25:17)

The question is asked why was Amalek considered worse than Sichon and Og, or the 31 other kings, who were involved in conquering the land?

The Shai L’Moreh explains that the answer lies in Amalek’s intent and objective in choosing to fight  with Klal Yisroel .

Usually war is instigated over money or land.  However, here Amalek was not fighting with Klal Yisroel for money, and they didn’t own any land.  

Amalek felt threatened by Klal Yisroel’s religion and emunah.  Until Bnai Yisroel left Mitzrayim the whole world was engaged in the worship of idols.  And the nation of Amalek was the major player in this practice.   When the Bnai Yisroel were taken out of Mitzrayim , Hashem performed the miracle of Kri’as Yam Suf which was very impressive. And the posuk relates (Shemos 15:15)  “az nivhalu alufei edom eilei mo’av yochazeimo ro’ad namogu kol yoshvei k’noan – then the chieftains of Edom were confounded, trembling gripped the powers of Moav, all the dwellers of Canaan dissolved.”    And the name of Hashem Yisborach became a powerful force in the world. 

 Amalek saw the underpinnings of his support  weakening because after such great nissim were done for Klal Yisroel many people began to convert to join the Bnai Yisroel. This is what Amalek came to fight about.  He wanted to destroy the emunah, and bring the people back to avodah zoroh. 

 Amalek set out to wage war against Hashem, and that is why his punishment was so great.  The kings of Sichon and Og, and the 31 other kings, were fighting over money and over land.  Theirs was not a war of theology.  Therefore there is no particular mitzvah to hate them and wipe them out.