While the announcement is almost certainly bluster to bring attention to illegal immigration and fentanyl smuggling, there are several reasons why it is so risky.

Mexico and Canada are the United States’ top two trading partners, accounting for nearly 30% of trade volumes.

The governments of China and Mexico warned of retaliatory trade actions and Canada urged restraint Tuesday after President-elect Trump on Monday threatened steep tariffs to pressure those countries into cracking down on drug trafficking and illegal immigration.