Thanks for the review. The article doesn't require that any values be shared, it only states what values lead to morality. What percentage of people share these values (freedom and reason) isn't within the scope of my writing. And values outside of these two aren't relevant for meta-ethics.

As to the scenario you laid out, the issue relates to ethics rather than meta-ethics that the article is about, but I'll still address it. The values of freedom and security would have to be justifiable to someone else. We wouldn't let someone's irrational paranoia guide national security policy, and any reasons provided when making policy (and in the social contract) would need to be public and comprehensible to all that are affected.

And any national security policy would have to be guided by the reason-based moral principles of the social contract. If it goes outside of those principles and acts arbitrarily, then it loses its morality and hence its political authority (imagine a requirement that all redhead people be subject to a special reporting requirement). Only reason has the authority to decide the rights vs. security question. and there will be a range of acceptable policies that respect the boundaries of the social contract. And political communities can give different priorities to the social contract's moral principles based on the national facts and circumstances (it must still value those principles, but it can apply them and prioritize them differently based on reason). See here for a discussion on how the social contract can specify rights.

And the error in the last section was treating X's freedom and Y's freedom separately. Freedom is an objective property that cannot reasonably be differentiated. Its not agent-relative, it is agency. There is no X's freedom or Y's freedom, there is only freedom that both X and Y happen to possess.