How has the ability of aircraft to observe changed since ww1

At the start of the First World War, aircraft like the B.E.2 were primarily used for reconnaissance. Due to the static nature of trench warfare, aircraft were the only means of gathering information beyond enemy trenches, so they were essential for discovering where the enemy was based and what they were doing. Prior to World War I, airplanes and other flying contraptions like dirigibles and hot-air balloons were used primarily for reconnaissance. In 1911, the Italians — at war with Turkey — dropped hand grenades onto enemy troops from a German-built monoplane, marking the first offensive use of an airplane in war

Explanation:

the treaty of brest-litovsk was a peace treaty signed on 3 march 1918 between the new bolshevik government of russia and the central powers (german empire, austria-hungary, bulgaria, and the ottoman empire), that ended russia's participation in world war i.