This week's U.S. metal tariff hikes and the instant retaliation from Europe and Canada are likely only the opening salvos in a global trade conflict that President Donald Trump appears intent on ratcheting up in less than three week's time.
The rhetoric shows no sign of compromise.
"Whatever they charge us, we're charging them," Trump told reporters at the White House. "We will not stand idly by," Canada's Finance Minister Dominic LeBlanc said of the latest tariffs moves.
There is background tension in Europe too as Germany's dramatic fiscal reforms and defence reboot now need to pass through parliament, with the Green Party's necessary support still not secured.
The Bundestag lower house of parliament will on Thursday hold the first reading of the proposal, which electrified European markets last week. A vote is due next Tuesday.
Back stateside, the focus will be on the Senate. If it doesn't support the Republican-backed stopgap funding bill, a partial government shutdown could be triggered as soon as this weekend.
The whole picture means U.S. stock futures have reversed all of Wednesday's modest bounce in the S&P500. And stock benchmarks across Europe and Asia are also in the red.
Meanwhile, Treasury yields pushed higher, batting away better-than-forecast consumer price inflation numbers on Wednesday, as the tentative stock market stabilisation reduced Federal Reserve easing bets once again. The dollar index was also off slightly.
CPI numbers are now very much in the rear-view mirror for a Fed waiting to see the impact of tariff hikes, so today's producer price numbers should also have little market impact.
But what could have quite a bit of market impact over the long term is the growing sense that the tumult in Washington could threaten the U.S. position as the world's safe haven.