The Church was extremely influential during the medieval ages. They held the ability to disperse information because churches were scattered all over Europe. This enabled their network of monks and priests to share information very fast. Furthermore, they collected taxes from peasants very often in the form of goods (farm produce for example), this made them very rich. They also had control over decisions which different rulers did as they could exile them which wasn't something any ruler wanted.
Islam spread extensively along the east coast of Africa by foreign traders.
German Emperor William i believe
The U.S. stimulated their economy be giving them a lot of money that then helped them kickstart their political return
Japan needed abundant natural resources to support both its population and its empire, something that the country lacked.
