Formalized politeness is also a cover. I remember a senior military officer deployed to Afghanistan. On week one he met with all the local leaders, drinking tea in countless houses. But by week two many of those same leaders were shooting at his people. The officer didn't understand that when he was new he was protected as a "guest" but that enforced politeness was never going to be permanent. Crossroad countries like Afghanistan/Iran have long support traders moving through and have cultures to support such travelers. But as soon as one is longer moving through, one shifts from honored guest to despised invader.

Many westerners in places like Japan speak of extreme politeness early on, but radical changes once you stay long enough to no longer be a guest in an area. Then the knives come out. Want to rent an expensive apartment in Tokyo as an english teacher? Cool. Hoops to jump but it can be done. Want to buy one of those cheap houses in rural Japan? Heck no.