GuessAnime.

Tokonatsu Taichi took the summer Koshien by the storm as a sensational ace pitcher, with a full arsenal of pitches including a 98 mph fastball. But on the way home from the game, the team bus suffered a tragic accident and Tokonatsu Taichi lost his life... Only to be transported to a new world where all international conflicts are resolved by a game of baseball. Unfortunately, the country he landed in was the weakest, and had seen gradual loss of its resources and people to neighboring countries. Can Taichi turn their fortunes around?

Source: MU

In Another World where Baseball is War, a High School Ace Player will Save a Weak Nation is finished and has 10 Volumes and 38 Chapters. It is also Known as: 野球で戦争する異世界で超高校級エースが弱小国家を救うようです, Yakyuu de Sensou suru Isekai de Choukoukoukyuu Ace ga Jakushou Kokka o Sukuu Youdesu

Genres: Action, Comedy, Drama, Fantasy, Magic, Shounen, Sports, Baseball, Isekai