Last Thursday President Trump announced that the US would impose new tariffs on imports of steel and aluminum. This caused US stocks to sell off broadly, while shares of the largest US steel makers got a small boost. The initial market reaction was small compared to the potential larger consequences of these policies. According to a recent note from Fidelity Investments, "the broader issue is the potential of escalating anti-trade policies globally, which could slow, or even reverse global economic growth and spur inflation."