The United States did not directly engage in battle.
In order to answer this you need previously to know that by a proxy war:
by definition:
is an armed conflict between two states which act on instigating third parties, usually setting terrain where hostilities take place. there must be a direct, long-term relationship between external actors and the belligerent groups involved.
Clearly there was no direct fighting between Soviet and American troops, still, the mujahedeen were economically assisted and tactically aided by Us officers whereas, to the counterpart, the communist local government that was supporting assistance from the Soviet side also was given financial and military assistance. In this ideological confrontations, the external powers do not engage in open and direct warfare, rather, the intermediate or states in between are the terrain for the war to be carried.
The correct answer should be monetary standard.
Grover Cleveland who won wanted the gold standard while his opponents supported bimetalism.
I believe its checks and balances but I may be wrong
