Original sentence: A nuclear Iran in the region would severely increase the risks to Western countries (particularly the United States) of nuclear attack, and could potentially act as a catalyst for other middle eastern nations to develop weapons of their own, furthering this problem.However, a potential reason behind US resistance lies in Middle Eastern geopolitics.Since 2002, the US has insisted that Iran does not need nuclear power due to its abundant oil reserves since, it argues, nuclear power is more expensive to generate than oil power.The particular type of nuclear power Iran is pursuing is termed by critics as being dual-use technology—i.it can be used for peaceful energy generation, but the same technology, it is argued, could also be used to develop nuclear weapons, the same sort of situation which resulted in India's own nuclear weapons programme in the 1960s
Edited sentence: A nuclear Iran in the region would severely diminish US influence, and could potentially act as a catalyst for other middle eastern nations to develop weapons of their own, thus further diminishing US influence.However, the core reason behind US resistance lies in Middle Eastern geopolitics.Since 2002, the US and Israel have singly has countered that Iran does not need nuclear power due to its abundant oil reserves since, they argues, nuclear power is more expensive to generate than oil power