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

Voting in federal elections is a responsibility that is exclusive to United States citizens. This civic duty is a fundamental aspect of democratic governance, allowing citizens to participate in the selection of their representatives and influence national policies. Only U.S. citizens have the legal right to register and cast their ballots in federal elections, a privilege not granted to non-citizens.

While paying taxes is also a responsibility that applies broadly, both citizens and non-citizens can be required to pay taxes in the U.S. Similarly, serving on a jury is a civic duty that often includes permanent residents in some contexts, depending on local laws, but it is primarily understood as a responsibility for citizens. Defending the Constitution is a broad principle of civic duty that applies to all American residents, but it is especially connected to the responsibilities of citizenship. Hence, voting in federal elections distinctly stands out as a responsibility solely for U.S. citizens.