Which event caused tensions in europe to become a full-scale world war? a. the assassination of archduke francis ferdinand b. the launch of the hms dreadnought c. the rise of communism d. the use of german u-boats

fourteenth amendment

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.