Let us not confuse the issue...China/Pakistan oppose it because they don't want India to get more nuclear capabilities...But, CPI/CPM oppose the deal because, they don't want such extra nuclear capability by SURRENDERING INDIA'S SOVEREIGNTY TO THE USA...Unless one goes into the details, one cannot understand how India will be badly mauled by the USA in the future if this agreement is signed. But, going into such details is outside the scope of this small post...