How did native communities respond to the Europeans? Did all native groups everywhere view the arrival of the Spaniards in the same manner? What prompted many native communities to make alliances with the Spaniards instead of fighting (or continuing to fight)?

They were welcoming in most areas, they were nice enough to give them food, shelter and plenty of other things.  No, not every native group viewed them as good people, and because they brought many bad things along with them. plus with all the, enslavement and plundering for gold that the Spanish did one thing really benefited the natives were the horses they were taught how to tame. from then on they didn't have to hunt or walk on foot.  The Spaniards had more equipment, guns they could uses against the native Americans

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.