The sending of the Zimmermann Telegram to Mexico was the reason off the declaration off war to Germany From the US. It taked a while for the Us entered the war, the first did with expeditionary forces but later also with more troupes. Aldo the Us was not very good the Germans had problem because the Us war machine good turn without having problems like bomming. And the Americans had many fresh troupes while the other country's had send many men to the front and many off them had died.