It was never under DOD in peacetime. It was part of Treasury for 177 years before it moved over to the Department of Transportation in 1967 and then to DHS in 2002.
Upon declaration of war, or when directed by the President, the Coast Guard becomes a Service within the Navy with the Commandant reporting to the Secretary of the Navy (he reports to the Chief of Naval Operations for military functions concerning the organization, training, and readiness of operational forces assigned to the Navy). The Coast Guard is a military Service and a branch of the Armed Forces of the United States at all times. It is a Service in DHS except when operating as part of the Navy on declaration of war or when the President directs.
The Coast Guard, whichever administrative structure it falls under, offers the best compromise on that question as well as the institutional abilities to carry out the various missions. The Coast Guard already guards our nations "border sovereignty" by guarding our sea lanes.
The US Navy guards our sea lanes.
Maintaining the integrity of the borders requires some different skills and lots of additional and different equipment, but it's the same mission. In addtion the CG has a great tradition of responding to natural and man made disasters. Finally they are not covered by Posse Comitatus and have police powers, unique in the US Armed Forces.
The US Coast Guard's mission is to protect the public, the environment, and U.S. economic interests – in the nation’s ports and waterways, along the coast, on international waters, or in any maritime region as required to support national security. It has about 39,000 military personnel and 7,000 civilians.
I'd model new CG units on Marine Expeditionary Units and base them at strategic points along our southern border. Add in the ability to move such units from their bases to anywhere in the continental US to respond to disasters and you have a interesting force structure. I'd start by stealing an MEU or two on rotation out of Iraq. Move them to the new bases and have them start setting up camp as traditional MEUs. Give them the mission of border control under emergency conditions. Call for volunteers from each MEU to form the core of a new cadre. Keep them and transfer out the rest of the MEU as you get in new CG recruits to fill billets.
What you are proposing is a new, land based mission for the CG. We already have 10,000 border patrol agents in DHS who are doing the same thing. What we need are more border patrol agents, physical barriers, and technology to control our southern land border with Mexico. The Coast Guard is tasked with protecting our sea coasts. Why create a new mission for the Coast Guard?
Yes, but you know what I meant.
What you are proposing is a new, land based mission for the CG. We already have 10,000 border patrol agents in DHS who are doing the same thing. What we need are more border patrol agents, physical barriers, and technology to control our southern land border with Mexico. The Coast Guard is tasked with protecting our sea coasts. Why create a new mission for the Coast Guard?
The border patrol ain't cutting it and they are too tied up with "la Migre" to be anything but "the enemy" to immigrants. If they are moved in as part of the CG structure you have a very good beginning of the force structure necessary. Add in the MEU type RDF under the CG command structure and tradition and I think you have a winning formula.
It's all about how they are perceived.
The BP has an image which is both incapable of doing the job and universally perceived as "the bad guys." How many movies can you think of where border patrol types were the bad guys? I can think of quite a few. Now, how many movies can you think of with CG types as the bad guys? I can't think of any.
And the drug cartels would s**t bricks.