Claiming that a shoal or Island sitting in your harbor should remain the property of another sovereign nation is obviously a ridiculous argument. You couldn't see how ridiculous it was until I pointed out how it would look as applied to Manhattan.
Had the British kept it, you would have been okay with it?
I don't think so. Spain is still bitching about Gibraltar.
So you support Spain’s claim to Gibraltar?
Your logic that SC had to take over Ft Sumter because it was next to SC is like the man who only wanted a small farm and all the land next to it.
Of course a foreign entity will be next to your country. To demand otherwise is to follow the logic of the Japanese during and before WWII: They needed Korea to secure their home islands, they needed Manchuria to secure Korea, they needed the rest of China to secure Manchuria, they needed Indochina to secure China, they needed Dutch East Indies to secure Indochina, and they needed the Philippines to secure Dutch East Indies....