If Ukraine falls, it will be hard to spin as anything but a debacle for the United States, and for its president.

The FTSE 100 ( ^FTSE) and European stocks were mixed on Wednesday after Wall Street slumped last night and China’s currency hits a 16-month low on Trump tariff fears.

The effect of new tariffs under consideration by US President-elect Donald Trump is unlikely to be "significant or persistent," a senior Federal Reserve official said Wednesday.