From Alan Taylor’s American Colonies: The Settling of North America:
Ironically, the French also came to depend upon Iroquois hostility as a barrier that kept the northern Indians from traveling south to trade with the Dutch. The French recognized that they could not compete with the quality, quantity, or price of the Dutch trade goods. Therefore, a prolonged peace with the Iroquois would tempt northern Indians to carry their furs to Fort Orange for shipment to Amsterdam—to the detriment of Quebec and Paris. The French could ill afford friendship with the Iroquois, although they paid a heavy price in death and destruction for their enmity. The Five Nation Iroquois became equally ambivalent about peace with the French. The Iroquois usually preferred to steal furs from their northern enemies to take to Fort Orange, rather than permit them as friends a free passage to the Dutch traders. Because the northern Indians possessed better furs, they would, in the event of peace, become the preferred clients and customers of the Dutch, to the detriment of the Iroquois. As inferior suppliers of furs, the Iroquois had a perverse common interest with the French, an inferior source of manufactured goods. They both tacitly worked to keep apart the best suppliers of furs (the northern Indians) and of manufactures (the Dutch).
And today France is a rich country thanks to all the good middle class jobs this Iroquois protectionism helped save.