Most were prospectors and pretty much everyone in general everyone wanted a little bit of gold you know.
Foreign traders were welcomed into Chinese ports during the Song dynasty. The song dynasty was an era in the Chinese history that began in the year 960 and ended around 1279 due to a war with remnants. The song dynasty was founded by Emperor Taizu of Song. During the Song dynasty, the Chinese allowed other people from foreign countries to come to their ports and traded with them. Since they allowed foreigners to come and trade with them, they got a lot of valuables. Because fighting with remnants of the dynastic court, the song empire ended in the year 1279, after the fall of the song dynasty, the Yuan empire began.
The fact that Germany invaded France if your talking about the First World War
If your talking about the second it was because Germany invaded Poland and Britain had an alliance with Poland promising to protect it.