Since the partition of the subcontinent in 1947, the geopolitics of South Asia has been shaped by a dynamic triangular relationship among Afghanistan, India and Pakistan on which depend prospects of peace, governance and stability in the South Asian region. This article examines how and why the Afghanistan–India–Pakistan triangle emerged and how it affects the entire South Asian region as a matter of geopolitics. The article also analyses why major strategic and political shifts occurred in these complex relations after the fall of the Taliban rule in Afghanistan in 2001 and ventures to provide some comments on more recent developments. The evolution and nature of the triangular engagements lie in the overlapping policies of these three countries. Hence, I identify their interactions as constituting a dynamic triangle. This article argues that strategic positioning and concerns and claims for political space have shaped their relationship to such an extent that if something bad happens in one of the three countries, this affects the position of the other two as well. That is why the current re-alignments in Afghanistan have crucial implications for the whole region, not just in terms of their respective foreign policy objectives but also for the long-term harmony, peace, progress and stability in the whole region.