Because we wanted their land, so we took it from them. <span />
The Chinese empire has been subject to unfair unilateral treatment for centuries. As foreign powers such as the Portuguese and the British sought to get their hands on this country's riches. This can be seen during the Opium Wars, which led to the colonization of the ports of Macao and Hong Kong, by the Portuguese and British respectively.
The military power exercised over China by foreign powers was replaced by the economic power of this same nations in the form of foreign investment that comes to China and sets up manufacturing sites that set unideal working conditions for Chinese locals at the expense of the enrichment of these businesses.
Feudalism is a system run by multiple nobles who look over provinces they rule under the kings authority. Democracy is a system in which government officials are elected by the people, or a group to run the nation until reelection or death.