What stopped the civil war between Nationalists and Communists in 1937?

What would lead a historian to consider two events to have a relationship of correlation rather than causation?

What does the document of the birtish octopus is an uderlying cause of the world war 1

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?