▁to ▁negoti ate ▁peace ▁in ▁Europe , ▁but ▁when ▁Germany ▁began ▁un rest rict ed ▁sub marine ▁war fare ▁against ▁American ▁sh ipping ▁in ▁early ▁ 1 9 1 7 ▁he ▁called ▁on ▁Congress ▁to ▁declare ▁war . ▁Ign oring ▁military ▁affairs , ▁he ▁focused ▁on ▁diplom acy ▁and ▁fin ance . ▁On ▁the ▁home ▁front ▁he ▁began ▁the ▁first ▁effective ▁draft ▁in ▁ 1 9 1 7 , ▁raised ▁bill ions ▁through ▁Liber ty ▁lo ans , ▁im posed ▁an ▁income ▁tax ▁on ▁the ▁wealth y , ▁set ▁up ▁the ▁War ▁Indust ries ▁Board , ▁promoted ▁labor ▁union ▁growth , ▁super vised ▁agricult ure ▁and ▁food ▁production ▁through ▁the ▁Food ▁and ▁F uel ▁Control ▁Act , ▁took ▁over ▁control ▁of ▁the ▁rail ro ads , ▁and ▁suppress ed ▁left - wing ▁anti - war ▁movements . ▁Like ▁the ▁European ▁states , ▁the ▁United ▁States ▁experiment ed ▁with ▁a ▁war ▁economy . ▁In ▁ 1 9 1 8 , ▁Wilson ▁advoc ated ▁various ▁international ▁re forms ▁in ▁the ▁Four teen ▁Point s , ▁among ▁them ▁public ▁diplom acy , ▁freedom ▁of ▁navigation , ▁" equality ▁of ▁trade ▁conditions " ▁and ▁removal ▁of ▁economic ▁bar riers , ▁an ▁" im partial ▁adjust ment ▁of ▁all ▁colonial ▁claims ", ▁the ▁creation ▁of ▁a ▁Polish ▁state ▁( the ▁Second ▁Polish ▁Republic ), ▁and , ▁most ▁important , ▁the ▁creation ▁of ▁an ▁association ▁of ▁nations . ▁The ▁latter ▁would ▁become ▁the ▁League ▁of ▁Nations . ▁The ▁League ▁became ▁highly ▁controvers ial , ▁for ▁Wilson ▁and ▁the ▁Republic