THE symphony of the global trade war conducted by the Trump administration appears to be returning to its central theme: a US-China showdown. One of the climactic movements is expected to come today, as Washington’s trade envoy is set to announce the final ruling on its port fee proposal.

Maritime communities, especially in China, are anxiously awaiting details on how much these fees will be and how they will be charged.

The once-tough port tax on China-built ships may soon see its edges softened, as Washington weighs trimming the measures or dropping the stacked charges — an idea floated by USTR Jamieson Greer after a wave of industry opposition.

Per-call fees might be reduced to a level tolerable enough to minimise avoidance or circumvention if the White House’s aim is to maximise revenue.

“This is like a 10% baseline tariff the US has already levied on global trade; few countries are disputing that,” said Zhou Qi, partner at Shanghai-based law firm Sloma & Co, during a recent industry event in China.

But the tax base could widen to increase the quantity collected; for example, non-Chinese ships calling at US ports could still be targeted if they are part of a fleet with China-built vessels.

Chinese yards have already buckled up, admitting in private that some owners are cancelling or postponing newbuilding orders, even where the buyer has no US exposure.

“Irrespective of whether their ships call in the US or not, [the fees] have become a negotiation leverage,” said one shipbuilding executive, adding discounts for China-built tonnage in charter and second-hand markets would inevitably spread to newbuilding prices.

As a result, margins could fall and capacity expansions may backfire. More efficient private yards are expected to fare better than their state-owned counterparts; and among state builders, those without naval business will worry more than those who have it.

“Rather than a Japanese or South Korean comeback amid labour shortages in those countries, I worry more about the rise of a new shipbuilding nation like India that could replace us,” said the executive. “Historically, the latter seems more likely.”

For many, beyond the level of fees, a key question is how long the policy could last. Will it be quickly exempted or reduced like many Trump tariffs, endure for years under this administration, or become part of a long-term strategy to revive US shipbuilding?

If you side with Bridgewater chief investment officer Ray Dalio’s view that shifts in world order won’t cease until the current superpower struggle produces a clear winner, the third scenario seems more likely.

And if the fees persist long enough that Chinese leaders see a threat not just to Chinese shipbuilding dominance but survival, a larger and more destructive retaliatory measure could be put on the table.

Beijing could levy reciprocal charges on ships not subject to US port fees, forcing shipping firms to use China-built hulls to carry Chinese cargoes.

This would further disrupt global trade and shipping, as vessels would have to pay fees at one side’s ports between the world’s two largest economies in the absence of transhipment.

It then hinges on whether China would sacrifice the wider industry for its shipbuilders — or rather, how much it is willing to pay to avoid defeat by Washington.