The Americans argue that such tough enforcement mechanisms are needed, given China's history of failing to keep its promises.
They think that only by offering tariff reductions for good behaviour, and threatening new tariffs for backsliding,
can they ensure that the Chinese keep their side of the bargain. But the Americans may have to give some ground, since the Chinese also have grounds for mistrust.
One of the reasons Mexican and Canadians agreed to rewrite their trade deal with America last year
was the prospect of tariffs on steel and aluminium thereby being lifted. Months later, those tariffs are still in place.
Business lobbyists in Washington seem resigned to tariffs being phased out only gradually as agreed-upon milestones are passed.
Recent evidence on the effects of the Trump administration's tariffs imposed in 2018 suggests that Americans will pay the price.
A study by Mary Amiti of the Federal Reserve Bank of New York, Stephen Redding of Princeton University
纽约联邦储备银行的Mary Amiti，普林斯顿大学的Stephen Redding
and David Weinstein of Columbia University found that American importers were swallowing the cost of tariffs by paying higher prices,
and that they were responding by importing a narrower range of products.
Another study, by Pablo Fajgelbaum and Amit Khandelwal of the National Bureau of Economic Research,
国民经济调查局的Pablo Fajgelbaum和Amit Khandelwal
Pinelopi Goldberg of the World Bank and Patrick Kennedy of the University of California, Berkeley,
世界银行的Pinelopi Goldberg以及伯克利加利福尼亚大学的Patrick Kennedy的另一项研究
found that although some American producers gained from weaker competition from imports,
that was outweighed by losses to consumers and other producers, who had to pay more for inputs.
It seems unlikely that the Trump administration will be swayed by this evidence of collateral damage.
Indeed, it may see buyers' struggles to adjust to tariffs as evidence that they were too dependent on Chinese exports in the first place.
Although a deal may see an easing of the tariff regime, from the administration's perspective it has been too successful to abandon altogether.
Americans had better get used to higher prices.