Complex sentence: The French in New France's heartland, Canada, opposed attacking the Province of New York because they were reluctant to arouse the Iroquois, whom they feared more than the British, and with whom they had made the Great Peace of Montreal in 1701.
Split into simpler sentences: The French in New France's heartland, Canada, opposed attacking the Province of New York. They were reluctant to arouse the Iroquois, who they feared more than they did the British, and with whom they had made the Great Peace of Montreal in 1701.