The Defense Department is in charge of Petite homeland security, attacks, invasion, and all war related activities. The "War" Department has never invaded, or attacked another nation, this is because the Federal Republic of Petite does not form or take part in imaginary wars. The War Department has only once declared war and have to make the homeland secure. 

The War Department also has a special code for sending messages to the president. While on the topic, a Military Delegate has a meeting with the Petite President every week. Only once has a meeting been canceled. While it's with a Military Delegate and for the the War Department, it's usually the President debriefing the War Department on Petite news and progress. The War Department was not always the War Department. The original name was way to long. It was called the "Homeland Security, Defense, and Invasion Department". This Department was dissolved and in turn, the War Department was formed.