The existing nuclear nonproliferation order has been steered by the United States as the preponderant power of the post-Cold War environment. The main challenge to the order from within – the emergence of “nuclear aspirants” has been epitomized by the Iranian nuclear program, which has been on the agenda of the international community for the past 10 year. Simultaneously, this period is also known as the rise of new powers, which by and large subscribe to the international order but question its interpretation by the United States. This paper looks at how two democratic rising powers – India and South Africa, engaged and challenged the American interpretation of the global nonproliferation norms. This paper tries to map out the responses of the two countries towards Iranian nuclear challenge and explain the appearance of the dissent by both changing power structure and shifting perception of self and own interests in the new international environment.