When considering minimum standards, and levels of preparedness I believe that in keeping with America's very important theme of being a free people, this concepts implementation, though very smart and practical, should be left up to each states local governments or their state governments. Moving on to what exactly is owed by a local government for the protection/safety of its citizens I believe Principle 24 of the American Founding Principals says it best when it says "A free people will not survive unless they stay strong. ‘To be prepared for war is one of the most effectual means of preserving peace.' - George Washington". Expanding on the statement above I would say that when it comes to the protection/safety of citizens one of the most important ways a government can do that is through making sure the people stay strong.
When it comes to a local government's duty to protect, and how exactly this duty should be balanced among a local government's other duties is quite simple. Every state is different, and going even farther every local government is different, therefore the simple solution to figuring out where protection stands among a local government's duties is simply by figuring out where a certain governmental duty stands in terms of protecting its citizens against threats to their freedom. If the protection/safety of citizens is a much more dire need in one local government than it is in another then that government's duty to protect its citizens should vary.
I believe that when taking into consideration the increased demands on scarce resources the most important option for meeting the requirements of public safety rest in teamwork. One local government may have an abundance of resources in order to provide for their citizen's protection while another local government may have next to none, but when teamwork is brought into the mix there then creates the possibility for both local governments to ensure proper protection for their citizens. The best example of the above idea can be found in "Introduction to Homeland Security" where it discusses the programs that exist in order to help fund or support homeland security for state and local governments (Bullock, Haddow, & Coppola, 2016, p. 143), or in other terms they use teamwork to accomplish the very important task of protecting the citizens of America.
References
Bullock, J., Haddow, G., & Coppola, D. (2016). Introduction to Homeland Security (5th ed.). Waltham, MA: Butterworth-Heinemann.