Whether in the US, UK or elsewhere, the more dissatisfied and afraid people become, Homer-Dixon says, the more of a tendency they have to cling to their in-group identity – whether religious, racial or national. Denial, including of the emerging prospect of societal collapse itself, will be widespread, as will rejection of evidence-based fact. If people admit that problems exist at all, they will assign blame for those problems to everyone outside of their in-group, building up resentment. “You’re setting up the psychological and social prerequisites for mass violence,” Homer-Dixon says. When localised violence finally does break out, or another country or group decides to invade, collapse will be difficult to avoid.