(11-22-2016 01:03 PM)MplsBison Wrote: That's a good enough answer.
I still question why that has to be a separate branch of military, and why that can't just be a function of the Navy ... but that ain't gonna change. No more than Marines being assumed into the Navy.
Coast Guard has a blended mission.
They are on patrol for activities hostile to the US (anything from tracking subs to waiting out an invasion fleet) but also serve a law enforcement role for customs and rescue and safety role.
It is an 8 year enlistment contract and generally four of those years have to be active duty.
During hostilities they get pulled in because they have the ships and experience to handle shallow water operations in rivers and deltas. In World War II they were driving a lot of the landing craft and performing search, rescue and evac on the beaches with other craft. Used a lot in Vietnam, did some missions with Iraq I and II and helped with transport issues in Afghanistan, even got involved in support for Kosovo.
Why are they are treated as military?
One is because they are subject to being brought into combat situations. It is cheaper to deploy the Coast Guard than have the Navy maintain a redundant system that is rarely used.
The Navy cannot perform the Coast Guard's roles on American rivers, lakes and coast because it is heavily a law enforcement role. The Posse Comitatus Act of 1878 limits Army (and later amended to add the Air Force) in the enforcement of US law within the US. The Navy has adopted regulations that track the Act so that they will not permit the Navy or Marine Corps to do anything the Army or Air Force is specifically barred from doing within the US. The Navy for example permits a naval vessel to track or stop a suspected drug running boat but they will only detain until the Coast Guard can arrive, they won't board, search or arrest. The Navy wasn't included in the Act because there was really no state analogy to National Guard / State Militia at the time that could perform state law and order missions and the territorial limit of the US waters was only three miles. The Navy wasn't expected to do much in the territorial waters of the US nor was there much fear of the president using the Navy against the public as a result.
So the Coast Guard is military because sometimes they need to be but kept outside the Department of Defense except when called into missions to avoid the situation of having the Pentagon doing law enforcement within the US.
Hope that helps.