Secure routing protocols for mobile ad hoc networks provide the required functionality for proper network operation. If the underlying routing protocol cannot be trusted to follow the protocol operations, additional trust layers, such as authentication, cannot be obtained. Threat models drive analysis capabilities, affecting how we evaluate trust. Current attacker threat models limit the results obtained during protocol security analysis over ad hoc routing protocols. Developing a proper threat model to evaluate security properties in mobile ad hoc routing protocols presents a significant challenge. If the attacker strength is too weak, we miss vital security flaws. If the attacker strength is too strong, we cannot identify the minimum required attacker capabilities needed to break the routing protocol. In this paper we present an adaptive threat model to evaluate route discovery attacks against ad hoc routing protocols. Our approach enables us to evaluate trust in the ad hoc routing process and allows us to identify minimum requirements an attacker needs to break a given routing protocol.