Complex sentence: This lead to a halt in military development, meaning the uniform remained practically the same from 1864 till World War I. With the increased risk of a German invasion in 1914, there again was focus on modernizing the army, leading to the M/15 uniform.
Split into simpler sentences: This lead to a halt in military development, meaning the uniform remained practically the same from 1864 till WWI. However with the risk of invasion in 1914, there again was focus on modernizing the army, leading to the M/15 uniform.