Moroni had originally attempted to exchange prisoners. His clear intention was not simply the exchange, however, but the cessation of the war. Since it was now clear that the war would continue, the desire to exchange the prisoners is less, even if the imperative to rescue his own people remains important. Moroni decides to retake his people who are held prisoners by stratagem and force rather than exchange.
“I Will Not Exchange Prisoners with Ammoron”
Moroni draws an interesting conclusion from his anger. Since Ammoron will not exchange prisoners and leave, Moroni does not want to increase Ammoron’s army in any way, if it can be helped. Likely Ammoron’s quick acquiescence to the exchange reminded Moroni that it really was to Ammoron’s advantage to have fewer people to feed, and to have the return of battle-hardened troops. Moroni decides to deny Ammoron that advantage.