The Illinois would persist during this period in denying their holding of any Fox slaves, but the French were impotent to force the Illinois to return the slaves in their possession. This in turn caused tensions to boil over and spark the Second Fox War. By the end of the Second Fox War, France had lost a trading partner, and a certain amount of economic influence. Another aspect that was made apparent through these tensions was the lack of control over the trade that New France had found itself to be reliant on. This lack of control stemmed from the political nature of the slave trade and the adeptness at which Illinois natives had used it to anger the Fox and lock the French into alliances. As a result, this was another event that led to the decline of the French power in Great Lakes Region.