There are many sourcese.g. 1,2, that discuss what happened to the world after the splitting of the sea, and the giving of the Torah, implying that the whole world heard what happened. Everyone knew about Hashem and the Torah. E.g. how Amalek came and cooled those "hot waters" of faith in Hashem.
Do any sources discuss how this affected free will? Do any sources explain exactly why this sort of free-will reducing event was able to happen, and why then and only then? (and seemingly when Moshiach comes as well, but that's a different question)
1 - Is there a midrash that says all of the water in the world split at the time of the splitting of the reed sea?
2 - The Torah offered to other nations