What was the purpose of the presidos

it was to transform Native Americans into Christians and loyal Spanish subjects. A presidio protected a mission. Presidios were forts that offered safety from unfriendly Indians. They helped soldiers to control Indians in the missions and catch Indians that ran away.

Explanation:

the right answer for the question that is being asked and shown above is that: "their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful.  " the  participant in european imperialism is being described below is that  their policy of "divide and rule" pitted political groups against each other to keep any one group from becoming too powerful. 

to keep us neatruel and not get involved in any wars

he assumed control of treaty negotiations with a hostile power