Original sentence: He could not believe that Japan would commit an act of war without a formal declaration, and had been assured by his ministers that the Japanese would not fight.Japan, in response, made reference to the Russian attack on Sweden in 1809 without declaration of war, and the requirement to declare war before commencing hostilities was not made international law until the Second Hague Peace Conference was held in October 1907
Edited sentence: He could not believe that Japan would commit an act of war on a neutral country especially without a formal declaration, and had been assured by his ministers that the Japanese would not fight.Japan, in response, made reference to the Russian attack on Sweden in 1809 without declaration of war, and the requirements to declare war before commencing hostilities and not attack neutral countries on land and sea wasn't made international law until the Second Hague Peace Conference was held in October 1907