The ultimate purpose of the Nation of Israel’s mission is to teach Torah to the entire world (which is what Amalek attempts to prevent). Israel’s influence over the nations of the world depends upon our acceptance of the Torah in our hearts. The more that we willingly internalize this, the more we can teach it to the world.
Teaching Torah to the world (the Fourth Revolution) began when the Nation of Israel embarked on its mission to conquer the Land of Israel – when Joshua wrote the Torah on the stones on Mount Eval in seventy languages. This is an invitation to all the nations to embrace the path of truth. Later, at the end of the Babylonian exile, there is another Jewish leader who speaks seventy languages. His name is Mordechai, and he was also called Ptachya, which means “God opened” because he opened his mouth in seventy languages.
Joshua and Mordechai have something else in common, as well. Joshua is the first Jewish leader to fight Amalek, as directed by Moses. Mordechai is the last Jewish leader to fight Amalek (until the generation of Mashiach). On the surface, spreading Torah to the world and fighting Amalek are two opposites: universalism as opposed to nationalism or even racism. But in truth, one is dependent upon the other. The war of Amalek against the Nation of Israel is primarily against Israel’s influence in the world. Amalek injects doubt and coldness even in Israel and certainly chills the nations of the world to Israel’s message. He claims that perhaps we have ethereal, heavenly messages, but there is no place for them in this world of practical politics. For Israel’s message to reach the nations, we must eliminate the doubting, chilling, mocking Amalek. This is the nature of the war and the proof is that when Amalek does accept Israel’s influence by means of conversion, there is no longer any commandment to destroy him. Amalek who surrenders himself to the Torah of Israel is no longer Amalek.
What is the connection between Joshua and Mordechai? Joshua writes the Torah in seventy languages. He teaches the Written Torah to the nations of the world. Mordechai-Ptachya opens his mouth in seventy languages. He teaches the Oral Torah to the nations of the world. What new dimension was actualized in Mordechai’s generation that made this leap possible? The Midrash relates that the generation of Moses and Joshua willingly accepted the written Torah, but that God had to ‘hold the mountain (Mt. Sinai) over their heads like a tub’ to convince them to accept the Oral Torah. In Mordechai’s generation, however, the Jewish Nation accepted the Oral Torah willingly (“the generation accepted it in the days of Ahashverosh”). Purim is the point of transition from the era of the Written Torah, the miracles of the Bible – to the era of the Oral Torah, which began to flourish in the Second Temple era.
What we learn from this is that we can only teach what we have willingly accepted. The Jewish Nation is expert at accepting the yoke of Torah. It can also fulfill the commandments under coercion. But to be a light unto the nations, we can only teach what we have integrated into our hearts. Amalek can claim that the Torah that we fulfill with a feeling of coercion and estrangement is foreign and irrelevant to the world. But from the moment that the inner dimension is revealed inside us – and we willingly and lovingly embrace the Torah – his claims become irrelevant.
We may erroneously believe that we can teach the external parts of the Torah to the world outside us, as this is the broadest common denominator, while the inner, personal aspect of the Torah belongs only to the Jewish Nation. But just the opposite is true. The only way that we can reach out to the external world is to adopt our most internal world. Hence, the more that increasingly internal dimensions of the Torah are discovered, the more that our motivation to overcome every doubt and heresy and to teach Torah to the entire world increases.
 Shabbat 88a.