Of course, the there is a game theoretic reason to shoot the messenger. The whole point of doing so is to burn a bridge. The original meaning of the term is:
Originally in military sense of intentionally cutting off one’s own retreat (burning a bridge one has crossed) to commit oneself to a course of action
Ancient battles, and probably to large extend in modern battles as well, were won or lost on moral. When a large part of your army panicked and ran your side was almost certain to loose. Furthermore, whoever was the last to run would be the first one killed when the enemy overran your position. Thus, if you were afraid the soldier next you would run, you were likely to run as well. Burning the bridge behind you was one way to resolve the game theoretic dilemma. Running cannot save your life, so you might as well hold the line.
Metaphorically burning a bridge by killing the messenger serves the same purpose. By publicly killing Sauron’s messenger Aragorn is reassuring his allies that he’s not going to betray them by cutting a deal with Sauron that leaves them out to dry.
Furthermore Aragorn et al specifically saw this conflict as a one-shot dilemma that had to be definitely resolved with the absolute destruction of Sauron. They already knew what negotiated peace with the enemy looked like (Saruman) and were not willing to risk that outcome, or any other outcome that would result in the rise of Sauron again. This is why they risk everything by making a frontal assault on Mordor against overwhelming odds. Killing the messenger / burning bridges is perfectly in line with the character motivations here and actually a point where the original source material fails.
Of course, the there is a game theoretic reason to shoot the messenger. The whole point of doing so is to burn a bridge. The original meaning of the term is:
Ancient battles, and probably to large extend in modern battles as well, were won or lost on moral. When a large part of your army panicked and ran your side was almost certain to loose. Furthermore, whoever was the last to run would be the first one killed when the enemy overran your position. Thus, if you were afraid the soldier next you would run, you were likely to run as well. Burning the bridge behind you was one way to resolve the game theoretic dilemma. Running cannot save your life, so you might as well hold the line.
Metaphorically burning a bridge by killing the messenger serves the same purpose. By publicly killing Sauron’s messenger Aragorn is reassuring his allies that he’s not going to betray them by cutting a deal with Sauron that leaves them out to dry.
I am pretty sure Aragorn followed virtue ethics, not consequentialsim. Abandoning honour for game-theoretical reasons wouldn’t have appealed to him.
Furthermore Aragorn et al specifically saw this conflict as a one-shot dilemma that had to be definitely resolved with the absolute destruction of Sauron. They already knew what negotiated peace with the enemy looked like (Saruman) and were not willing to risk that outcome, or any other outcome that would result in the rise of Sauron again. This is why they risk everything by making a frontal assault on Mordor against overwhelming odds. Killing the messenger / burning bridges is perfectly in line with the character motivations here and actually a point where the original source material fails.