Why not simply renounce your citizenship now if you feel you should owe no duty to maintain any kind of national security policy?

Private citizens don’t maintain the US’ national security policy, as this article clearly shows, but you are commenting on a theoretical reality that has lacked consensus or wasnt even on the table during every administration of the same country.

Alternatively, US citizenship doesn't guarantee any beneficiary of national security or evacuation from another place when shit hits the fan.

So before I answer your question, what did you mean specifically?