OTTAWA, Nov 23 (Reuters) – Canadian Prime Minister Justin Trudeau's government learned a lesson when former U.S. President Donald Trump forced the renegotiation of the North American trade pact five years ago: never underestimate U.S. protectionism. Taking that lesson to heart has prompted Canada to mirror U.S. strategy in the Pacific and tout itself as an alternative to China for vital clean technology materials in the hope that becoming a long-term strategic partner of the United States will insulate it from protectionist impulses in the future. In recent speeches to Washington policymakers and in its foreign policy alignment with the…