The Defense Department has identified gaps in the nation’s homeland defense stemming from potential maritime threats but Northern Command (NORTHCOM), which is responsible for the defense of the continental United States, does not have a detailed plan for responding to these threats, the Government Accountability Office (GAO) says in a new report.

The current plan requires U.S. Fleet Forces Command, which is the joint force maritime component commander for NORTHCOM, to provide a supporting plan for maritime security, which gives NORTHCOM “critical details on how operations are to be conducted” thereby enabling it to understand “which subordinate commands are prepared to support the maritime homeland defense mission,” says the report, Homeland Defense: Actions Needed to Improve DoD Planning and Coordination for Maritime Operations (GAO-11-661).

According to GAO, DoD identified three maritime homeland defense gaps related to engaging and defeating maritime threats.

“The three maritime homeland defense capability gaps may affect DoD’s ability to coordinate maritime operations with relevant interagency stakeholders and respond to the full range of potential threats in the Northern Command maritime area of responsibility,” GAO says. “For example, the assessment noted that the command lacked a robust understanding of the roles and responsibilities of its interagency partners, thus limiting the extent to which it could effectively coordinate interagency operations in response to maritime threats. Further, the assessment noted that the command’s ability to respond to certain threats without timely warning might be inadequate.”