Triangulation is a manipulation tactic where one person will not communicate directly with another person, instead using a third person to relay communication to the second, thus forming a triangle. It is also a form of splitting in which one person manipulates a relationship between two parties by controlling communication between them.
From my perspective this happens between tribes,countries,any group of people.
Also easy to not be aware of internally, I for example if simply know two people, and all three of us know each other, (bob,jane and myself). I am alone with jane, and say something negative about bob, this is why one has to be very aware of any negative ideas we project, as this in a reality, negative to all three people, the foundation of the splitting of the group, tribe, culture.
Early on in this video Teal Swan brings up " Triangulation" (17:20 - 18:59 ), I like how she impress's the point that the individual is pushed away, thus threaten it's survival,it's identity as part of the pack!, This is Serious stuff, yet we are so un-aware of ourselves culturally anymore, We are un-aware that humans only thrive as a tribe, the very essense of our being, this is why I made the page "Purple Stage-the much needed"
This is why Simone Weil's book " Need for Roots " is so symbolic,
Nature gives us all the clues needed to survive with harmony, if we pay " Attention " , one for example is nearly all high brain developed species are part of a pack,tribe,group. this is the reason for page " Alone-life on one's own planet"- I know of no human being whom could survive very long, completely alone, or at least do well.