The DoD is probably safe to continue, but will still be scrutinized. All they have to do is change the name of the Department of defense to the Navy. The U.S. Constitution gives Congress the power to maintain the navy through Article I, Section 8, Clause 13:
Provide and maintain a navy: Congress has the power to provide and maintain the navy.
Make rules and regulations: Congress has the power to establish rules and regulations for the navy.
Raise and support armies: Congress has the power to raise and support armies.
The DoD is probably safe to continue, but will still be scrutinized. All they have to do is change the name of the Department of defense to the Navy. The U.S. Constitution gives Congress the power to maintain the navy through Article I, Section 8, Clause 13: Provide and maintain a navy: Congress has the power to provide and maintain the navy. Make rules and regulations: Congress has the power to establish rules and regulations for the navy. Raise and support armies: Congress has the power to raise and support armies.
DoD needs to protect ONLY the United States. All else shut down.