"You need cooling, my friend"

I have deemed it my duty, therefore, to say to the Imperial German Government that if it is still its purpose to prosecute relentless and indiscriminate warfare against vessels of commerce by the use of submarines, notwithstanding the now demonstrated impossibility of conducting that warfare in accordance with what the Government of the United States must consider the sacred and undisputable rules of International Law and the universally recognized dictates of humanity, the Government of the United States is at last forced to the conclusion that there is but one course it can pursue and that unless the German Imperial Government should now declare and effect the abandonment of its present methods of warfare against passenger and freight-carrying vessels, this Government can have no choice but to sever diplomatic relations with the Government of the German Empire altogether.

President Wilson's
Address to Congress,
April 19, 1916.