In which conflict did the u. s. pursue a policy of isolationism before becoming involved in hostilities?
a: the spanish-american war
b: the korean war
c: world war 2
d: the civil war in rwanda

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.