Analysis: The president has been announcing tariffs for months, but his latest moves are opening salvos in potentially drawn-out tit-for-tats with dozens of countries and countless repercussions.
Any doubt that the president was "all talk" about tariffs has been put to rest amid a flurry of tariffs, threats and retaliatory duties going into effect in a matter of weeks.
Relations between Greenland and Denmark have been strained in recent years, but Trump’s interest in controlling the island has prompted Copenhagen to hasten to improve ties.