According to an alternate reading of Sanhedrin 74a cited by Mesoras HaShas §20 ad. loc., in a time of religious persecution, one must give up his life even for a “light mitzvah.” The Gemara 74b identifies this, according to Rashi’s explanation, as wearing one’s shoes in the manner of the non-Jews when the Jews had a different way of wearing them.
What is considered “persecution” to fulfill this criterion? Must it be widespread to the point that if practically any non-Jew sees a Jew on the street he’ll attack him? Or a majority? Or even a decent percentage? At what point is it considered “a time of persecution” that a Jew would be required to give up his life rather than even dress like a non-Jew?