The importance that these events brought was the intervention of the united states in the war.
During the european war between russia, france, great britain, serbia and japan against the central powers : germany, austria, turkey and the ottoman empire, the united states decided to stay on the sidelines.
The sinking of the Lusitania ( with the loss of american civil lives) caused by the german forces, generated a tension between the united states and germany.
Even worse was the telegram Zimmerman (secretary of foreign affairs of the german empire) who instigated the mexican goverment to declare war on the united states, promising large areas of us territory. The telegram was intercepted by the british and was revealed to the authorities of the united states.
The tensions between the united states and germany had become to o great and the united states declared war on germany.
