Close relationships are, at the same time, a source of risk and a resource that can mitigate risk, fear, and insecurity. Specifically, close relationships provide the potential for rejection and hurt, but a) close others can behave in ways that diminish these perceived relational risks to encourage deepening connection, and b) involvement in close relationships can mitigate risks external to relationships (i.e., risks in the physical and social environment) to facilitate personal thriving. This chapter will describe the relational risks individuals face when they form interdependent relationships as well as partner behaviors that demonstrate commitment and promote trust (e.g., sacrifice, affectionate touch) to reduce the perceived cost of interdependence. Although all people are subjected to risks when they form interdependent relationships, individuals differ in the extent to which they perceive risks and in the ways in which their partners might mitigate these risks. People with insecure attachment orientations (i.e., high levels of attachment anxiety and/or attachment avoidance) are especially concerned with relational risks, and they benefit when partners enact behaviors that are sensitive to their specific insecurities. In addition to relational risks, this chapter will also describe how partners regulate external risks that people face when they experience threats (e.g., stressors, health problems) or opportunities (e.g., goals, positive challenges). Research suggests that supportive and affectionate partner behaviors provide a sense of security to mitigate external risks and encourage exploration, which may be especially critical for individuals with insecure attachment orientations. Finally, this chapter will conclude with suggestions for future research.