This is an excerpt from a speech given by President Woodrow Wilson to Congress in 1917. Vessels of every kind, whatever their flag, their character, their cargo, their destination, their errand, have been ruthlessly sent to the bottom without warning and without thought of help or mercy for those on board, the vessels of friendly neutrals along with those of belligerents.
In this excerpt, Wilson was explaining which reason for the United States’ involvement in World War I?

discovery of the Zimmermann Telegram

discovery of the Zimmermann Telegram

sinking of merchant ships by Austria-Hungary

sinking of merchant ships by Austria-Hungary

start of the Bolshevik Revolution in Russia

start of the Bolshevik Revolution in Russia

use of submarine warfare by Germany

use of submarine warfare by Germany