Yawn.
This is dicta. I've given you an example of a treaty that is SO FAR beyond the scope of the Constitution that there is no question it should not be allowed to stand. It stands.
Show me a case where a provision of a treaty has been ruled unconstitutional and thereby invalidated. Name one.
“Show me a case where a provision of a treaty has been ruled unconstitutional and thereby invalidated. Name one.”
The article clearly states that none have been invalidated. It does give case citations where the courts have stated that treaties must be IAW the Constitution.
In the theoretical case you’ve advanced, it would come down to whether the 2nd Amendment addresses a collective or an individual right. IOW, nothing has changed.
Now that I’ve had another cup of coffee, I would like to make another comment.
If your theory is correct, this theory could be used to amend the Constitution in any number of ways. For example, a President negotiating in secret with a single foreign power could propose a treaty to Congress and this treaty could be enacted by three members of Congress. This treaty could enact a President for Life, re-instate slavery, or any number of things all without following the amendment process. Do you think the founders intended to give such powers to the federal government? Surely, they foresaw this possibility. The obvious inference is that they did and considered treaties to be co-equal with other laws passed by the Congress but subordinate to the Constitution. This is entirely consistent with the case citations and the article provided.