What was significant about the united states in the end of the 1800 to 1900s?

Which of the following descriptions is an example of the curtual diffusion

The military dictatorship inviolently reacted to the opposition of the maya, who demanded greater rights for their native population. the genocide inresulted from a struggle between arab nomadic tribes and non-arab agricultural groups. the tutsi were the victims of genocide inat the hands of the hutu rulers.

The quote below is an excerpt from the charter of the united nations: "the purposes of the united nations are: to maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace . " source:this section implies that the united nations is prepared to do what to keep world peace?