Subterranean Border Defense Act

This bill amends an existing reporting requirement in the 2023 National Defense Authorization Act. It changes the provision to require the Department of Homeland Security to submit annual reports on counter-illicit cross-border tunnel operations, rather than just one report after developing a strategic plan. The bill does not create new programs or alter border security policy; it only modifies the frequency of required reporting. This procedural change directly affects the Department of Homeland Security's reporting obligations.