From BBC NEW
US President Donald Trump has shaken the foundations of global trade, slapping steep tariffs on billions of dollars’ worth of goods from the EU, Canada, Mexico and China.
All these countries are responding in kind, retaliating with levies on thousands of US products.
This puts the world’s largest economies at each other’s throats.
But what is a trade war? How does protectionism work? And how will it all affect you?