▁behind ▁him , ▁Franklin ▁Ro ose vel t ▁had ▁just ▁been ▁elected ▁to ▁his ▁second ▁term ▁as ▁the ▁President ▁of ▁the ▁United ▁States ▁in ▁ 1 9 3 6 . ▁ ▁The ▁same ▁year ▁he ▁selected ▁Dr . ▁Thomas ▁Par ran ▁to ▁be ▁the ▁Sur geon ▁General ▁of ▁the ▁United ▁States . ▁ ▁Three ▁years ▁later , ▁in ▁ 1 9 3 9 , ▁Dra per ▁was ▁selected ▁as ▁the ▁Deput y ▁Sur geon ▁General , ▁a ▁position ▁he ▁would ▁hold ▁until ▁his ▁ret irement ▁in ▁ 1 9 4 7 , ▁working ▁under ▁Dr . ▁Par ran ▁for ▁the ▁entire ▁duration . ▁ ▁The ▁division ▁within ▁the ▁Sur geon ▁General ' s ▁headquarters ▁responsible ▁for ▁l ia ison ▁with ▁the ▁states , ▁where ▁Dra per ▁had ▁been ▁in ▁charge , ▁was ▁then ▁turned ▁over ▁to ▁Dr . ▁Joseph ▁Walter ▁Mount in . ▁ ▁As ▁the ▁Second ▁World ▁War ▁progress ed ▁in ▁Europe ▁from ▁ 1 9 3 9 ▁to ▁ 1 9 4 1 , ▁the ▁direct ▁invol vement ▁of ▁the ▁United ▁States ▁appeared ▁im min ent . ▁ ▁While ▁isol ation ists ▁cl am ored ▁against ▁U . S . ▁invol vement , ▁the ▁attack ▁on ▁Pear l ▁Har bor ▁in ▁December ▁ 1 9 4 1 ▁put ▁an ▁end ▁to ▁such ▁sent iments , ▁and ▁the ▁subsequent ▁declaration ▁of ▁war ▁against ▁the ▁United ▁States ▁by ▁Germany ▁and ▁Italy ▁allowed ▁for ▁a ▁clean ▁entry ▁by ▁the ▁Americans ▁into ▁the ▁European ▁Theater . ▁ ▁Pl anning ▁for ▁the ▁invasion ▁of ▁Europe ▁began