File No. 763.72111/3509g
The Secretary of State to the Italian Ambassador (Macchi di Cellere)
My Dear Mr. Ambassador: In accordance with your request, I am enclosing memorandum issued by the Department on September 19, 1914, which defined the general rules this Government then felt should be followed in cases involving the status of armed merchant vessels visiting American ports.1
Since this memorandum was drawn up the situation has been changed by the use of submarines as commerce destroyers, and for that reason this Government feels that these rules should be modified, as a small caliber gun on a merchant ship is just as effective for purposes of attack against the submarine as the large caliber gun. Therefore, the presence of any gun on a merchant ship of a belligerent nationality could well create presumption that the armament was for offensive purposes, thereby causing this Government to treat the ship as a ship of war.
I am [etc.]