That which is worth doing may involve suffering. Some amount of suffering seems to me to be the price of human being human. Where it it needed it is not to be avoided. Where it is not needed it should not be accepted needlessly. It is not the suffering that makes it worth the doing, nor the pain experienced which accomplishes the task.

In your case of WW II it is not by and large the ones who died who made the difference. Rather it was the ones who survived to complete the mission.

Cheers,
Ben