Is this the moment the 2018 trade conflict became a war?

The U.S has already opened up multiple battle fronts by imposing tariffs on metal imports from Canada, Mexico, and the European Union.

But applying duties of up to 25 percent on $34 billion worth of Chinese imports from this Friday, with China threatening immediate retaliation, is the start of something much bigger.

Between them, these two countries drive a third of global economic output.

And this battle looks set to escalate quickly, with Trump threatening additional tariffs on imports with a combined value of $400 billion.

But even if the value of these initial tariffs is small, the effect is disproportionately large.

European car makers who manufacture here in the U.S illustrate this.

Hit first by U.S. tariffs on European steel imports, they now face the double whammy of tariffs when they export from the U.S to China.

No wonder German automaker Daimler was first out of the blocks with a profit warning.

Others are equally exposed. I’ve twice visited Iowa on reporting assignments and talked to farmers who are increasingly dependent upon exporting to China. They’re now afraid they’ll suffer the effects of China’s retaliatory tariffs for years.

So, where does this end?

U.S. President Donald Trump has used tariffs as leverage against China to try to change what he calls unfair trade practices – everything from China allegedly undercutting U.S competitors to forcing U.S companies to hand over trade secrets to their Chinese business partners. China denies these practices, insisting it’s committed to open and fair trade.

Conflicting signals suggest there may be room for negotiation.

As this tariffs deadline loomed, the U.S decided to temporarily ease some restrictions on Chinese telecoms firm ZTE after U.S companies were banned from trading with it.

Yet 24 hours earlier, the Trump Administration asking regulators to block China Mobile.

The window for averting a full-scale trade war appears to be closing, as these two behemoths – completely interdependent and whose every economic move ripples across the world – are no longer officially talking to each other about how to stop it.