What is one responsibility that is only for United States citizens?

Serving on a jury is indeed a responsibility that is uniquely designated for United States citizens. This duty is critical to the judicial system and serves as a cornerstone of civic engagement in the legal process. Only citizens have the right and obligation to participate as jurors in trials, reflecting the principle that a jury of one's peers should consist of individuals who have a vested interest in the community and its governance.

While paying taxes, voting in elections, and obeying local laws are also important civic responsibilities, they are not exclusive to citizens. Lawful permanent residents (green card holders), for instance, are required to pay taxes and must obey local laws, but they are not allowed to vote or serve on juries. This distinction highlights the unique role of citizenship in contributing to civic life and the workings of democracy in the United States.