One reason why Imperialism led to World War One is because it increased tension between countries whilst competition between them and the alliances were being formed. Each nation was eager to prove that they were the best of the best.
The main countries with tension were Germany and France. Prior to the World War One, Germany invaded Alsace-Lorraine, which made France weary of Germany and tension begun building up between the two countries.
Germany’s imperialism meant they begun building their army more and more. France, being at Germany’s border, would feel intimidated by their army and would start building up defences in order to show resistance and be able to defend themselves should Germany become a threat.
Africa was a hugely popular place to conquer as it had a lot of natural resources Britain and France quickly swept up most of Africa and in 1900 the only part of Africa left unconquered was Morocco in North Africa. This made Germany greedy and they were eager to take control of Morocco.
So, the competition between France and Germany got worse when both of them wanted to conquer the remaining parts of Africa. Germany believed it should belong to them as Britain and France already had control of the rest of Africa, however in 1904 Britain had agreed that France should be allowed to control Morocco.
The situation got even worse in 1911 when French troops entered Morocco and took it over. Germany then came in to help fight off France, but they failed and vowed to get revenge.