[BroJoeK]

x: "...the idea that Fort Sumter was some kind of unendurable threat to the whole state of South Carolina just won't fly."

Thanks! Three excellent analogies make this case:

1. British forts on US territory for years after the Revolutionary war.
   Brits maintained at least half a dozen forts in New York, Ohio and Michigan for up to 14 years after the Treaty of Paris in 1783.
   They were never considered a casus belli and were patiently negotiated away by John Jay's treaty of 1796.

2. The Japanese attack on Pearl Harbor exactly illustrates how the Confederate attack on Fort Sumter was unequivocally and act of war against the United States.

3. The US base at Guantanamo illustrates the fact that a change in government in Cuba in no way invalidates the US military's legal right to occupy its base there, just as the Deep South's declarations of secession in no way invalidated US ownership of forts, ships, arsenals & mints, etc. in those states.

[DiogenesLamp]

British forts on US territory for years after the Revolutionary war. Brits maintained at least half a dozen forts in New York, Ohio and Michigan for up to 14 years after the Treaty of Paris in 1783. They were never considered a casus belli and were patiently negotiated away by John Jay's treaty of 1796.

None of which maintained an array of cannons pointed at the incoming ships attempting to trade at any Primary port.

If you have an example of British maintaining forts overlooking the entrance to Boston's, New York's, or Philadelphia's harbors, then I will concede you have a point.