Did Trump just launch a trade war?

LAST Thursday, US President Do­­­nald Trump signed a proclamation to raise tariffs for steel by 25% and for aluminium by 10%.

It sent shockwaves across the world not only because of the losses to metal exporters, but due to what it may signify – the start of a global trade war that will cause economic disruption and may damage, if not destroy, the multilateral trade system.