The alliance systems were all formed at different times and some even moved around to different alliances, having alliances in WW1 was at large a rather good but bad idea seeing that when one member of their alliance was threatened or attacked they all came together and threatened the opponent back, sometimes when this happened the enemy would retreat. An example of this would be when the Archduke and his wife of Austria-Hungary were assassinated, the Austria -Hungarians were convinced it was Serbians were the ones that did this and so Austria-Hungary told Germany about it and Germany was ready to attack Serbia. Eventually Germany and Austria-Hungary made an alliance with Italy to stop them from supporting
The alliance systems were all formed at different times and some even moved around to different alliances, having alliances in WW1 was at large a rather good but bad idea seeing that when one member of their alliance was threatened or attacked they all came together and threatened the opponent back, sometimes when this happened the enemy would retreat. An example of this would be when the Archduke and his wife of Austria-Hungary were assassinated, the Austria -Hungarians were convinced it was Serbians were the ones that did this and so Austria-Hungary told Germany about it and Germany was ready to attack Serbia. Eventually Germany and Austria-Hungary made an alliance with Italy to stop them from supporting