An agreement between the U. S. and Germany, after the sinking of a passenger ship of the same name, that Germans would not torpedo any more ships containing Americans without warning.

Sussex pledge

Explanation:

The Sussex agreement was made after the sinking of SS Sussex in 1916 by German's torpedo. Around 50 passengers died from that attack.

After being condemned internationally, Germany agreed to create an agreement Several months later with Untied States. The main point of the Sussex pledge was :

- Germany would no longer attack passenger ships that came across their territory (assuming that those ships did not carry objects that are dangerous for Germany)

- Even if that ships are carrying war materials that might endanger Germany, the imperial navy agreed to let the passengers get out of the ship before they sunk it.