▁victory ▁at ▁Pear l ▁Har bor ▁and ▁thereby ▁lost ▁the ▁war ." ▁ ▁While ▁the ▁attack ▁accomplished ▁its ▁intended ▁objective , ▁it ▁turned ▁out ▁to ▁be ▁largely ▁unnecessary . ▁Un be known st ▁to ▁Yam am oto , ▁who ▁conce ived ▁the ▁original ▁plan , ▁the ▁U . S . ▁Navy ▁had ▁decided ▁as ▁far ▁back ▁as ▁ 1 9 3 5 ▁to ▁abandon ▁' charg ing ' ▁across ▁the ▁Pacific ▁towards ▁the ▁Philippines ▁in ▁response ▁to ▁an ▁out break ▁of ▁war ▁( in ▁keeping ▁with ▁the ▁evolution ▁of ▁Plan ▁Orange ). ▁The ▁U . S . ▁instead ▁adopted ▁" Plan ▁Dog " ▁in ▁ 1 9 4 0 , ▁which ▁emphas ized ▁keeping ▁the ▁I J N ▁out ▁of ▁the ▁eastern ▁Pacific ▁and ▁away ▁from ▁the ▁sh ipping ▁lan es ▁to ▁Australia , ▁while ▁the ▁U . S . ▁concentr ated ▁on ▁defe ating ▁Naz i ▁Germany . ▁ ▁Fort un ately ▁for ▁the ▁United ▁States , ▁the ▁American ▁aircraft ▁carri ers ▁were ▁un touch ed ; ▁otherwise ▁the ▁Pacific ▁Fle et ' s ▁ability ▁to ▁conduct ▁off ensive ▁operations ▁would ▁have ▁been ▁cri pp led ▁for ▁a ▁year ▁or ▁more ▁( g iven ▁no ▁divers ions ▁from ▁the ▁Atlantic ▁Fle et ). ▁As ▁it ▁was , ▁the ▁elim ination ▁of ▁the ▁batt les hips ▁left ▁the ▁U . S . ▁Navy ▁with ▁no ▁choice ▁but ▁to ▁rely ▁on ▁its ▁aircraft ▁carri ers ▁and ▁sub mar ines — the ▁very ▁weapons ▁with ▁which ▁the ▁U . S . ▁Navy ▁halt ed ▁and