Why Did Trump Suddenly Turn On China Again?

Everything seems to have settled down with President Trump's America and China now that they'd climbed down from their maximalist tariff barrage. But Trump doesn't do quiet and settled, and so he exploded the peace with a range of new measures targeting China, along with an explosive tweet where he accused them of breaking the 'agreement' they had previously reached. What caused it - and does this mean we're back into the spiralling world of consequences? Let's discuss.