This chapter explores the concept of a leap of trust and distinguishes it from other approaches to trust-building. It also explores how it became possible for Vajpayee to make his extraordinary trust-building move and the role that Sharif played in facilitating the Indian leaders leap. The starting point for thinking about the possibilities of building trust between India and Pakistan is recognition of the importance of the concept of the security dilemma. The chapter assumes that the Pakistani leader was genuinely committed to working with Vajpayee in developing a cooperative relationship. It does so by examining how far Sharif deceived Vajpayee by planning with his generals the attack at Kargil. The chapter considers whether the trust that had made possible the breakthrough at Lahore completely disappeared after Kargil. The concept of trust has been marginalised in the theory and practice of international relations and it argues that this has had negative consequences for exploring viable alternatives to a nuclear-armed world.