A Hobbesian trap is a situation where people cannot trust each other and so have to act in ways that help them survive. Imagine a village that is surrounded by dangerous animals. The villagers can't trust each other and so they need to all carry weapons to protect themselves. Nobody knows who will attack and so they all have to stay armed and ready to fight. This is a Hobbesian trap because even though they all want to be peaceful, they can't be and they have to act in a way that keeps them safe.