This is the argument that the Watchtower uses on their view of military involvement. They reason that if everyone were like them and refused to join the military, there would be no wars
I do think you have somewhat gone off at a tangent there.
JWs maintain non-involvement with the military on the grounds of what they like to describe as "Christian" neutrality, not pacifism (how could you anyway, when the bible is full of blood and guts talk). Furthermore, they maintain all wars will be ended by "Christ's Kingdom Rule", not pacifism.
As to the role of any imagined "Hereafter", the Canadian poet Robert Service summed it up perfectly in his poem The Wage Slave - part of which reads:
"When the long, long shift is over, and the Big Boss gives me my pay,
I hope it's not to hellfire, as I heard the preacher say,
And I hope it's not to heaven, not with some of the preachers I've met."
If even half the twerps that reckon they are going to heaven end up there, then I certainly don't want to be among them!
(Read so much for religion promoting good behaviour!)