<span>Because the plan was to surprise the Germans and to land in a place and at a time that they did not expect.</span>
An Arms-Build up would lead to peace due quite frankly, to fear. It would lead to peace, just like for example, North Korea. No one is allowed to have weaponry, meaning fear. No one attempts to revolt, due to fear. Having a militia, would enforce fear, causing no revolts, or riots, or anything of the sort.
The answer is animism.
Animisim refers to the belief system that attribute souls to non-living things.
These people believe that the non-living things had the capability to create either fortune or misfortune to the people near it. Currently, China and Indonesia have the highest population of animist in the world.