US President Donald Trump has upended international trade with his new tariffs.Donald Trump has slapped new taxes on any goods imported into the US – and economies around the world are reeling.It’s the topic on everyone’s mind this week amid fears that a trade war could soon erupt and disrupt the international market as we know it.Keir Starmer even warned “the world as we knew it has gone” over the weekend.But just how has one man managed to cause so much chaos? HuffPost UK steps back and explores exactly what just happened here.What has Donald Trump done?Trump announced