Why do you think countries desire empires? Explain

Because countries profits from their empire.

You see, with a vast territory all around the world (e. g. British Empire) they'll have a lot of men power, farmlands, natural resources, and manipulation over the World's trade routes. For example, China (modern and older Qing Dynasty). It's large farming territories mean that they won't suffer famines even they had the largest number of population. It's also improves it's population, for example is the German Empire; the largest industry player in Europe, with a high life expectancy and one of the wealthiest nation in the World, who formerly known as Kingdom of Prussia; a highly militarized nation, with poor civilian government. Few smaller nations, that consist of Netherlands, could actually be a colonial superpower, only because it's colony in Netherlands Indies, without actually conquering lands in Europe. In the other hand, Russian Empire before the time of Tsar Alexander I, were pretty backward, with small wealth and poor citizens.