Beijing’s relatively ambiguous response to the Ukraine War has tested how firm the Sino—Russian strategic partnership is. This article aims to decipher the endurance and complexity of Sino-Russian strategic relations by evaluating the nature and dynamics of Sino-Russian defense cooperation amid the worsening international environment against both countries. By examining two Sino-Russian Joint Exercises and analyzing their joint military patrols, exercises, and technological projects, this article argues that the general Sino-Russian military collaboration has been enhanced. Beijing and Moscow have gradually strengthened the combat orientation of their military cooperation to deter the perceived third-party threat, solidify their strategic partnership and against the challenges posed by conflicting interests in the overall bilateral interaction. Both Beijing and Moscow consistently remain vigilant against the risks of abandonment and entrapment, emphasizing the importance of maintaining strategic autonomy and refraining from formal alliances. However, they confront the worst-case scenario of being simultaneously dragged into two separate armed conflicts by a shared adversary. Therefore, align with their own national interests, the ability of Beijing and Moscow to achieve a delicate equilibrium between avoiding entrapment and preventing abandonment will determine the vitality and long-term trajectory of their strategic partnership.