What is one power of the states under the Constitution?

One power of the states under the Constitution is to provide protection through police. This responsibility falls within the states' authority to maintain law and order and ensure the safety of their residents. States are empowered to establish their own police forces and law enforcement agencies, which operate independently from federal law enforcement. This local governance allows states to address the specific needs and circumstances of their communities, reflecting the principle of federalism wherein states retain significant powers and responsibilities.

The other options do not accurately represent powers specifically granted to states. For instance, enforcing federal laws is a responsibility primarily of the federal government, while regulating international trade falls under the jurisdiction of the federal government as well. Issuing currency is an exclusive power of the federal government, which maintains control over the monetary system to ensure economic stability and consistency across the states.