▁Japan , ▁which ▁the ▁latter ▁perce ived ▁as ▁an ▁un friend ly ▁act . ▁The ▁United ▁States ▁did ▁not ▁stop ▁oil ▁exports , ▁however , ▁partly ▁because ▁of ▁the ▁prev ail ing ▁sentiment ▁in ▁Washington : ▁given ▁Japanese ▁dependence ▁on ▁American ▁oil , ▁such ▁an ▁action ▁was ▁likely ▁to ▁be ▁considered ▁an ▁extreme ▁prov ocation . ▁ ▁In ▁mid - 1 9 4 0 , ▁President ▁Franklin ▁D . ▁Ro ose vel t ▁moved ▁the ▁Pacific ▁Fle et ▁from ▁San ▁Diego ▁to ▁Hawai i . ▁He ▁also ▁ordered ▁a ▁military ▁bu il dup ▁in ▁the ▁Philippines , ▁taking ▁both ▁actions ▁in ▁the ▁hope ▁of ▁disc ou rag ing ▁Japanese ▁ag gression ▁in ▁the ▁Far ▁East . ▁Because ▁the ▁Japanese ▁high ▁command ▁was ▁( m ist aken ly ) ▁certain ▁any ▁attack ▁on ▁the ▁United ▁Kingdom ' s ▁S out heast ▁Asian ▁colon ies , ▁including ▁Singapore , ▁would ▁bring ▁the ▁U . S . ▁into ▁the ▁war , ▁a ▁dev ast ating ▁prevent ive ▁strike ▁appeared ▁to ▁be ▁the ▁only ▁way ▁to ▁prevent ▁American ▁naval ▁inter ference . ▁An ▁invasion ▁of ▁the ▁Philippines ▁was ▁also ▁considered ▁necessary ▁by ▁Japanese ▁war ▁pl ann ers . ▁The ▁U . S . ▁War ▁Plan ▁Orange ▁had ▁en vision ed ▁def ending ▁the ▁Philippines ▁with ▁an ▁el ite ▁force ▁of ▁ 4 0 , 0 0 0 ▁men ; ▁this ▁option ▁was ▁never ▁implemented ▁due ▁to ▁opposition ▁from ▁Douglas ▁Mac Ar thur , ▁who ▁felt ▁he ▁would ▁need ▁a ▁force ▁ten ▁times ▁that ▁size . ▁By ▁