Why is the vietnam war and example of a proxy war?

Explanation: the Vietnam War can be considered a "proxy" war in the Cold War. Although the Soviet Union and the United States did not directly go to war, they each supported a different side in the war. The Viet Cong were Vietnamese rebels in the South who fought against the Southern Vietnam government and the United States.

a historian researching the immigration policies of the early 1900s would expect a source written today,rather than in 1910 to :

( a ) be more interested in objective data and statistics.