President Donald Trump. Thomson Reuters Donald Trump has all but reneged on his three most crucial campaign promises on trade. Considering how out of touch with modern norms of international commerce those were, that's a good thing.

The president passed on naming China a currency manipulator and has yet to pull out of the North American Free Trade Agreement or impose the aggressive tariffs on imported products from China and Mexico that he touted on the campaign trail.

However, that does not mean Trump's protectionist rhetoric and the isolationist actions he has taken so far will not have a damaging effect on US trade relations and the economy.

The stealth nature of Trump's free-trade rollbacks makes them potentially more pernicious, since they could lead to a slow erosion of America's competitive advantage and, with it, the job market.

Just witness the recent watering down of a key statement by the Group of Seven major world economies, pushed for by the United States alone, so that it did not include an explicit commitment to free trade.

More substantively, the Trump administration has been taking targeted steps in various industries, including steel and agriculture, to pick fights with trading partners that may have damaging long-run effects.

On steel, Trump has cited national-security concerns to launch a widespread review that many worry could lead to new rounds of tariffs and trade disputes.

"This issue could come to a head imminently," the news website Axios wrote in its morning newsletter on Tuesday.

"The Trump administration has quickly adopted an aggressive and antagonistic approach to using US trade laws as a protectionist tool," Chad Bown, a former White House trade economist and a senior fellow at the Peterson Institute for International Economics (where I used to work), wrote in a new study.

"The effect on trade relations may not be as immediately disruptive as if Trump had followed through on campaign threats to pull the United States out of NAFTA or impose 45% tariffs on China," Bown wrote. "However, the escalating trade barriers and the means through which the Trump administration is motivating their use have the potential to severely weaken the rules-based trading system."

During the campaign, Trump even threatened to pull out of the 164-member World Trade Organization, which the United States played a key role in developing over several decades. Now the approach is less an all-out trade war than a cold war of trade attrition that threatens to be equally damaging — and could lead to severe job losses if implemented on an ongoing basis.

"Rather than blowing it up by simply withdrawing, the end result of the Trump administration's tactics may be that the World Trade Organization implodes from within," Bown said.

A Peterson Institute study published ahead of the 2016 presidential election estimated that if fully implemented, Trump's proposals on trade would "provoke retaliation by US trading partners, unleashing a trade war that would send the US economy into recession and cost millions of Americans their jobs." It estimated the potential hit to trade-related jobs, which include many in the service sector, down to the state level.

Along similar lines, the European Central Bank last week took the rare step of rebuking a sovereign state's leadership, arguing that the Trump administration presents a risk to the world economy.

"Since the US election, pressures for more inward-looking policies have risen," the ECB said. "In particular, there is significant policy uncertainty surrounding the intentions of the new US administration regarding fiscal and, especially, trade policies, the latter entailing potentially significant negative effects on the global economy."

The Bank for International Settlements also offered some indirect advice to the Trump administration on trade in its recently released annual report.

"Greater emphasis on measures that would hinder free trade in national policy agendas suggests that the risk of protectionism may be growing further," the BIS said. "A rise in protectionism would add to the cyclical and structural factors that have held back global trade post-crisis."