Politicians hate to have a real war with a powerful opponent. This kind of war will only hurt themselves or destroy themselves. Their purpose is not a real war. Politicians like to have a war with a remote and weak opponent. The threat of war can make people fear the invisible enemy. In this way, people will be willing to hand over their freedom, wealth and power. So politicians like war, so that they can gain the greatest power and plunder people's wealth. 

This is why the longer the war, the more the fiat currency depreciates.