Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: President Donald Trump's announcement that the US would impose a 25% tariff on the imports of steel entering the US has shaken the stock market and rattled some of America's closest trading partners.

Steel tariffs - what impact will they really have?