Premise
I would like to create a formula that tackles the question of how likely a civilization is to commit self-annihilation. At first glance it doesn't sound possible or practical for that matter. I concede it's difficult to formulate and is likely to not be 100% accurate. However, I think it has merit nonetheless. To quote one of my favorite statisticians George Box:
All models are wrong, but some are useful.
This mind-set is useful when discussing the self-annihilation of civilizations. For instance, Frank Drake didn't have the audacity to think he could actually quantify how many intelligent civilizations are in our galaxy when he formulated the Drake Equation:
$N=R_*\cdot f_p\cdot n_e\cdot f_l\cdot f_i\cdot f_c\cdot L$
Rather, the point was to generate scientific discussion and apply concepts as currently understood (Fermi paradox, ect). Another cool thing about the drake equation is that although it tries to model something ambitious like the number of intelligent civilizations, the right-hand side variables are mostly able to be objectively quantified. Then there is $f_i$, which is the fraction of civilizations that actually develop intelligence. It's unlikely that $f_i$ can ever be measured or guessed at accurately, but Drake put it in the model nonetheless. From this perspective, the Drake equation shows how much we know and can quantify and what remains purely conjecture.
Similarly, I hope that an equation formulating the likelihood of a civilization to commit self-annihilation can be informative and useful.
Question
In a similar spirit to the Drake equation, how can I create an equation that tries to model the likelihood of a civilization to commit weapons-based self-annihilation using as few purely conjectural variables (like $f_i$) as possible? The left hand side variable is $P$ (probability of self-annhilation). So the output is a probability between 0 and 1. To further make things more manageable, let's limit the specification to at most 7 right-hand variables only (7 is the number for the Drake equation, and it's a lucky number). This way we don't have to model a chaotic outcome that could have very high $k$ (right-hand variables).
- 1 meaning inescapable self-annihilation
- 0 meaning totally safe.
$P= ?$
Further Clarifications:
- Answer should fill in the right-hand side variables, $P=?$
- Answer doesn't have be an explicit formula, a list of right-hand variables is acceptable
- No worked out examples are required; I have one provided below for clarity, but I'm not trying to crunch any numbers yet.
- non-weapon related notions are out of scope; that's not to say they are not important, we're just simplifying things a bit.
- Priority is given to variables that are quantifiable
- Regarding model specification, you may want to consider if there are certain components of the model worth mentioning, interaction terms, quadratics (capturing diminishing effects), ect
- Up to 7 right-hand variables are permitted. We would want the variables with the most(dangerous word choice, I know) explanatory power, and other variables will be assumed to be zero.
Example These are strictly for illustration purposes; please do not over analyze them. That said, suppose a caveman civilization that is mostly peaceful but has a few marauding gangs, all with very primitive technology like wooden clubs and rocks. The probability of the few gangs wiping out the entire civilization should be low. Say: .000000001. In another world where everyone has access to nuclear bombs, John Doe is fired from his job and takes down the whole city with him -- such a world should have a higher $P$, say: .95.
I have included the weapons,society and technology tags accordingly. This is the extent of my research and thought-experiments; if you feel it necessary to broaden the scope beyond these fields, you may. Just explain in your answer.
Disclaimer: I realize there is a subjective nature to this question, but much in the same way that the Drake equation is criticized by some, it is still respected by many. I'm hoping that the science-based tag will allow us to evaluate answers in a qualitative, constructive yet still fun manner.