Complex sentence: The Canadian government reacted defensively towards claims that the fissionable material used to construct India's first nuclear device had been obtained from the Canadian-supplied CIRUS nuclear research reactor and, in a rash move, severed bilateral nuclear cooperation with both India and Pakistan in 1976.
Split into simpler sentences: The Canadian government was stung by allegations that the fissionable material used to construct India's first nuclear device had been obtained from the Canadian-supplied CIRUS nuclear research reactor. Canada severed bilateral nuclear cooperation with both India and Pakistan in 1976.