Because they had to pay for more materials to rebuild there buildings after the war
It transitions the US at least from a period of negative economic aura to a high economic aura.
Moral diplomacy was a major tool for the United States to pursue its economic interests abroad.
In the end, moral diplomacy increased the U.S.'s direct military action in many countries and also greatly impacted the economy by manipulating situations in countries that were not democratic or those that held what Wilson viewed as morally corrupt values.