This paper evaluates the impact of Indo-US strategic partnership on Pakistan’s security using the lenses of balance of power and power transition theories. A theoretical evaluation through these contending theories highlights the significance of the subject as it draws same results from the both. Although these theories are considered opposed to each other, both reach at the same conclusion when applied to the Indo-US Strategic Partnership and its impact on Pakistan’s security. The paper argues that power transition theory does not refute the balance of power theory in India-Pakistan context, rather it supports the latter. Changing the balance of power in South Asia is, in fact, an act of bringing transition. This analysis suggests that any power transition in South Asia shall disturb the balance of power in the region and may lead to war. The analysis, therefore, supports balance of power hypothesis that “if power balance is disturbed, it shall bring instability.” It also suggests that by changing the balance of power in India’s favour, Indo-US strategic partnership shall bring power transition in South Asia, and would therefore be perilous for Pakistan’s security.