Zero Sum Games & Nuclear War?

 In a recent article in the Guardian on a wargame conducted recently to investigate tension between Russia and Finland a reference  was given to a paper by Roger Mason [1]. This paper was all pretty standard stuff on the history of wargaming, but we have this at the start of the section covering the Cold War:

The cold war offered strategists, political leaders, and wargamers a new set of  problems. The challenge was the new age of nuclear weapons where strategic warfare might truly be a global zero-sum game.

This left me wondering exactly what did the author think or intend this "zero-sum game" phrase to mean in this context?

Lets look at the definition of a Zero Sum Game, here from Wikipedia:

Zero-sum game is a mathematical representation in game theory and economic theory of a situation that involves two sides, where the result is an advantage for one side and an equivalent loss for the other.^[1] In other words, player one's gain is equivalent to player two's loss, with the result that the net improvement in benefit of the game is zero.^[2]

 What would a zero-sum pay-off matrix for strategic nuclear war look like!? There seems to be a couple (or more) possiblities behind this quote: 

1. I don't understand what the author is getting at,

 or (more likely)
2. The author does not know what a zero-sum gave is, and is using the phrase because it makes him sound smart.

References

Mason, Roger, Wargaming: Its  history and  future, The International Journal of Intelligence, Security, and Public Affairs, V20, 2 pp 77-101, 2018.

Kinematics Countermeasures to Anti-Torpedo Torpedoes.

Back in 2019 at the Undersea Defence Technology (UDT)  conference (in Stockholm) I attended a talk on the Netherlands' navy introduction of Anti-Torpedo Torpedoes (ATTs), and asked a question "Have you considered the effect of Counter Countermeasures (CCM) on the effectiveness of the ATT". The presenter, knowing who I was (as I had just delivered a paper on using machine learning to optimise torpedo homing algorithms, the day before), replied that he would leave that to me.

On returning home I put together a paper on kinematic CCMs to ATTs, based entirely on open source material, and in my own time, in a week or so for the 2020 UDT conference.

Unfortunately, I developed medical problem (Oct 2019) that led to me giving notice of my retirement, and would have made me reluctant to travel for the next UDT conference, and the conference was cancelled anyway (early 2020?) due to the outbreak of a pandemic. So the paper was never delivered.

I have now posted it to my research gate account: PDF of paper is here.

This paper did not go through the full BAE (my employer at the time) vetting procedure (which it would have needed, as if I had delivered it at UDT I would do so as a representative of BAE), but as it was written on my time, and using open sources and I no longer represent BAE in any capacity, it should be OK to release it now. But note this does not necessarily reflect the views of BAE systems, doubly so as I don't know what their current view of ATT CCM are.