Japan has abolished its army and navy right after the second world war. Japanese army was the strongest and most aggresive army in the Asia, and the navy was world top 3、after British royal navy and US navy.
Then, Japan was the first country in the world to sink a battleship not by the cannon battleship or torpedo from the submarine but aerial attack, by aircrafts. Also built the world largest battleships, Yamato and Musashi. Ironically, both ships sank by air raids by US.
Although there is no army or navy, Japan has self defense forces. The self defense forces' functions are very limited and it is even take time to send peacekeeping force to third countries. Of course, there is no enforced conscription - not compulsory to join the forces.
Japanese self defense forces are protecting Japan and also dispatched when huge natural disasters occured.