I thought it was understood but since these are US bases I was referring to traitors against the US.
You are missing the point.
All Union veterans were traitors to the
United States, not traitors to South Carolina.
Treason is waging war on the States. If one says South Carolina is in the Union, then it is one of the states within the category "United States." To wage war on any state in the Union is treason. Nowhere does the Constitution says that the traitor must wage war on
all of them. Any of them will suffice.
Alexander Hamilton, a northern man who wanted an even stronger federal government than what came out of Philadelphia (like Putin, Hamilton wanted the central government to
appoint state governors, for example), and even Hamilton said this: "
Can any reasonable man be well disposed towards a government which makes war and carnage the only means of supporting itself  a government that can exist only by the sword? … But can we believe that
one state will ever suffer itself to be used as an instrument of coercion? The thing is a dream;
it is impossible." So maintaining a Union by war and carnage is, according to Hamilton, "unreasonable."
Further, Article IV, Section 4 stipulates: The United States
shall guarantee to every State in this Union a republican form of government, and
shall protect each of them against invasion." The Constitution does not say, "
may guarantee ... a republican form of government." It is a positive command. The US
must, it is
obligated to guarantee a republican form of government, so removing a republican form of government and replacing it with an appointed military government is a direct violation of the U.S. Constitution. And this was the primary reason Virginia seceded in 1861. When the Federal government does something violent, antidemocratic, and unconstitutional, good people stand up and say, "No. We will not do that."
Because I have an interest in living in peace in the same country with the descendants of the former traitors, it is best to let that be. But since you brought up treason ...