▁between ▁the ▁Soviet ▁Union ▁and ▁the ▁West ▁became ▁a ▁source ▁of ▁he ated ▁controvers y ▁among ▁sch ol ars ▁and ▁polit icians . ▁In ▁particular , ▁histor ians ▁have ▁sharp ly ▁disag re ed ▁as ▁to ▁who ▁was ▁responsible ▁for ▁the ▁break down ▁of ▁Soviet - U . S . ▁relations ▁after ▁the ▁Second ▁World ▁War ; ▁and ▁whether ▁the ▁conflict ▁between ▁the ▁two ▁super pow ers ▁was ▁in ev itable , ▁or ▁could ▁have ▁been ▁avoided . ▁Histor ians ▁have ▁also ▁disag re ed ▁on ▁what ▁exactly ▁the ▁Cold ▁War ▁was , ▁what ▁the ▁sources ▁of ▁the ▁conflict ▁were , ▁and ▁how ▁to ▁dis ent angle ▁patterns ▁of ▁action ▁and ▁reaction ▁between ▁the ▁two ▁sides . ▁ ▁With ▁the ▁opening ▁of ▁the ▁arch ives ▁in ▁Moscow ▁and ▁Eastern ▁Europe ▁after ▁ 1 9 9 0 , ▁most ▁of ▁the ▁pressing ▁issues ▁have ▁been ▁resolved . ▁ ▁The ▁" orth odox " ▁school ▁domin ated ▁American ▁histor i ography ▁from ▁the ▁ 1 9 4 0 s ▁until ▁it ▁was ▁challeng ed ▁by ▁both ▁Wisconsin ▁School ▁and ▁New ▁Left ▁histor ians ▁in ▁the ▁ 1 9 6 0 s . ▁The ▁orth odox ▁school ▁places ▁the ▁responsibility ▁for ▁the ▁Cold ▁War ▁on ▁the ▁Soviet ▁Union ▁and ▁its ▁expansion ▁into ▁Eastern ▁Europe . ▁Thomas ▁A . ▁Ba iley , ▁for ▁example , ▁argued ▁in ▁his ▁ 1 9 5 0 ▁America ▁F aces ▁Russia ▁that ▁the ▁break down ▁of ▁post war ▁peace ▁was ▁the ▁result ▁of ▁Soviet ▁expansion ism ▁in ▁the ▁immediate ▁post war