“Yisro, the minister of Midian…” (18:1)
Yisro, the minister of Midian, the father-in-law of Moshe, heard everything that Hashem did to Moshe and to Yisrael, His people (18:1). Yisro heard about the Splitting of the Sea and the Jews’ battle with Amalek, and this inspired him to join the nation (Rashi, citing Zevachim 116a).
In Sefer Kol Rom Hagaon Harav Moshe Feinstein zt”l asks: while the Splitting of the Sea was obviously a miracle, what was so outstanding about the war with Amalek? Perhaps the Jews simply defeated Amalek by natural means. Additionally, if the Jewish victory was so impressive, why didn’t Yisro mention it when he thanked Hashem for saving the Jews from the Egyptians – which included the miracles at the Sea (below, pasuk 10)? As a non-Jew, Yisro could have attained spiritual fulfillment, a share in the World to Come, and be considered a “pious non-Jew” by simply observing the Seven Noachide Commandments. Indeed, the Exodus from Egypt and its attendant miracles incontrovertibly showed Yisro that there is a G-d, and this demanded that he observe those seven G-d-given laws. Why, then, was he inspired to convert to Judaism?
What caught Yisro’s attention about the war with Amalek was not the Jews’ victory, but the Amalekite attack. After the Splitting of the Sea, there was universal awe of the Jewish People; “The chieftains of Edom were confounded, trembling gripped the powers of Moab, all the dwellers of Canaan dissolved” (above, 15:15). Yet Amalek was able to overcome that fear and ignore the many obvious miracles in order to attack the Jews.
This taught Yisro that without Torah, it is possible for a person – even an entire nation – to ignore all the miracles and even the dangers of attacking a nation obviously protected by Hashem. Amalek could still be so blinded by hatred as to attack Hashem’s people! When Yisro saw that, he decided that it would not be enough for him simply to be a good, fulfilled non-Jew. He would still be in danger of making serious errors. To avoid that risk, he decided to become part of the Torah nation.
So, Rav Moshe explains that true, the war with Amalek was part of the reason he joined the Bnei Yisrael, but it was not the Jewish victory that motivated him. It was the recognition that without Torah, an entire nation could make incomprehensible, even fatal, errors. It was that dimension of the battle that inspired him.