Whether focusing on the near or long-term, understanding the resilience of human societies in a global catastrophe (such as a devastating pandemic or nuclear winter) is key to achieving altruistic impact through planning and preparing for them. Others have made commendable efforts to assess, broadly speaking, how severe of an outcome is required to threaten human potential permanently, but our aim is to investigate some more concrete aspects of the world around us that should inform a model of how catastrophes might play out. This post discusses the initial findings of some research Anders and I have started into the role of the Armed Forces in helping to prevent a society from collapsing in such an event. 

A priori, one might expect military institutions to take on substantial responsibilities in the effort to keep civilisation running, given their apparent size and resources and the plot of every third Tom Cruise film. Engaging with UK and allied Joint Doctrine on analogous subjects has caused us to update and greatly narrow down our idea of how this might happen. 

How Military Aid to Civilian Authorities (MACA) would be employed in the face of an "emergency" (e.g. severe regional flooding, large terrorist attack, etc.) is described at length in UK doctrine. As a rough approximation, one could extend the scope of these regional emergencies to encompass the whole country, resembling the situation in some catastrophe scenarios. Thus, MACA is a best-case that can inform our upper limit as to how much support the military could provide. 

The linked document is explicit in ruling MACA to be a last resort (para. 205), with assistance from the emergency services of neighbouring regions and other local public services to be sought first. One might assume this is for political or security reasons, and these likely contribute to this ruling, but there is a strong practical justification also (para. 224):

• The size of the Armed Forces is small compared to the public services in total, and especially to the wider population. Depending on whether you count Service personnel under training, the UK military employs around 130,000 - 190,000 people. 
• Military capability, both skills and equipment, is optimised for carrying out expeditionary roles and for lethality. Military equipment is unusually good at carrying out warfighting tasks but may not represent an improvement in civilian resources in supporting the function of society. Indeed, the doctrine cited above predicts the whole Armed Forces to have an engineering capacity similar to, if not exceeded by, a medium-sized British town. 
• A huge amount of logistic and engineering support is provided to the military from civilian industry. Expecting this dependency to reverse in dire circumstances seems wholly implausible. 

Thus, we can rule out even medium-scale infrastructure support being deployed by the military. Nonetheless, it is worth clarifying which functions it could contribute. Next, I propose the Joint Doctrine Publication on overseas disaster relief operations as another best-case scenario. An economically deprived country in the wake of a vicious hurricane or tsunami is probably faced with challenges of a similar magnitude to that of people surviving a catastrophe. Of course, such relief operations rely on the industrial capacity of unaffected countries, which could not be expected in the scenarios we are considering. Hence, this provides us with another upper limit. 

A table of military capabilities relevant to disaster relief operations is presented in Annex D, which I include here for ease of reference. 

As with response to local emergencies, this table is quite sparse with respect to the provision of hard infrastructure and engineering. Instead, various applications of Command and Control (C2), coordination of existing efforts, and management more generally appear throughout. 

From this, we conclude that the main strength offered by the Armed Forces post-catastrophe is by having a substantial body of people ready and able to find workable solutions to practical tasks. This is the very essence of a military operation, and Service personnel will have deeper experience in achieving results in such situations of isolation and adversity than most other sectors of society. It is entirely conceivable that the fate of individual communities would depend on their ability to solve a few vital practical problems before resources dwindle and the military seems like one of the strongest bets for ensuring this can be done. Conflict of interest disclaimer: As a military officer, this paragraph makes me think "Phwooarr" in a forearm-flexing, bicep-clutching kind of way.

We intend to keep digging into this topic and others like it, to produce further contributions to this forum and/or develop these ideas into an academic paper. Our biggest obstacle at this stage is finding credible sources for the vast amount of research that has surely already been done on this topic, particularly during the cold war. Additionally, we focused on the UK to keep our initial investigation suitably bounded, but understanding how this line of reasoning might fall down for countries with a very different military makeup is essential. If you know of any relevant literature, professional contacts, or lines of thinking that might be interesting, please do let us know!