Wrong, Joseph. Since Avnei Nezer Yoreh Deah 312,49 where he explicitly states that the king has no business punishing Shabbat violators.
Regarding working for the government, what happened to civil society? In any case, there are three sheetot regarding how we can be a light unto the nations:
1. According to Rav Shimshon Raphael Hirsch it means being scattered among them until Mashiach comes.
2. According to Rav Kook (and expounded further by Rav Zalman Melamed) it means kibbutz galuyot, establishing a state in EY and being part of the community of nations.
3. According to the YU sheeta there ar two centers, the US and Israel.