In the post-war period American governments tended to side with the purists.

在战后时期，美国政府倾向支持纯粹主义者。
But according to Anne Krueger of Johns Hopkins University, writing in the Journal of Economic Perspectives,
但是约翰霍普金斯大学的安妮·克鲁格在《经济展望杂志》中写道，
by 1982 gridlock in multilateral talks meant it switched to a twin-track approach, simultaneously pushing for multilateral deals and negotiating preferential ones.
到1982年，多边会谈中的僵局意味着其转向双轨制，力图多边贸易的同时又协商特惠协议。
Chief among these was the North American Free Trade Agreement,
其中为首的就是北美自由贸易协定，
which came into force in 1994 and is due to be replaced by the United States-Mexico-Canada agreement (USMCA).
其于1994年生效并将被美墨加三国协议（USMCA）所取代。
The approach spread. Nearly 300 preferential trade deals are now recorded by the WTO.
这种方式传播开来。WTO现在记录了近300份特惠贸易协议。
Many go beyond tariff-cutting to include rules on state-owned enterprises, intellectual property and trade in services.
很多协议远不止关税减让，还包括针对国有企业的规则、知识产权以及服务贸易。
Having grown into an integrated trading area, the EU became an enthusiastic proponent,
EU已成长为了一个综合的贸易区，它变成了一位热情的支持者，
striking many reciprocal deals, including with Canada, Mexico and Singapore. In June it started talks with Australia.
和包括加拿大、墨西哥以及新加坡在内的多国签署了互惠协议。今年6月，EU开始和澳大利亚进行会谈。
As such deals proliferated, economists studied their impact. One fear had been that they might divert custom from more efficient producers in third countries.
随着这种协议的激增，经济学家研究了它们的影响。担忧之一是它们可能会转移第三国更高效生产商的关税。
But a paper by Aaditya Mattoo, Alen Mulabdic and Michele Ruta of the World Bank, published in 2017,
但世界银行的阿迪蒂亚·玛图、艾伦·穆拉比奇以及米歇尔·鲁塔于2017年发表的一篇论文发现
found that shallow deals do little to reduce trade with third countries, and deep ones tend to increase it.
这种浅薄的协议和减少第三国贸易关系不大，并且深入协议易于增加第三国贸易。
This, they think, is because rules on competition policy, subsidies and standards are hard to apply in a discriminatory way.
他们认为这是因为针对竞争政策、补贴和标准的规定很难以一种歧视性的方式进行。
But there is also reason to fear that preferential deals weaken the impetus towards comprehensive liberalisation.
但还是有理由担心特惠协议会削弱全面自由化的动力。
Nuno Limao of the University of Maryland, and others,
马里兰大学的Nuno Limao以及其他人发现
have found that America and the EU offered less tariff liberalisation in multilateral talks in product areas where they had already granted preferential tariffs in bilateral deals.
美国和欧盟已经在一些产区的双边协议中实施了特惠关税，而在这些地区的双边会谈中，美国和欧盟提供的关税自由更少。
Though previous American administrations were sometimes frustrated with the WTO, they viewed it as the foundation of the trading system.
虽然之前的美国政府对WTO偶感失望，但是他们将这视为贸易体系的基础。
Preferential deals were an instrument of diplomacy. TPP was intended to create a template for a trading system that might eventually include China,
特惠协议是一种外交手段。TPP曾旨在为一种最终包括中国的贸易体系创造模板，
and perhaps give reform-minded Chinese policymakers something to aim for.
并且有可能为决心改革的中国决策人提供目标。
Mr Trump's trade agenda could hardly be more different.
特朗普的贸易议程可能完全不同。
His "America First" rhetoric, threats of tariffs on allies and of withdrawal from the WTO,
他的“美国优先”策略、对盟国施加关税和退出WTO的威胁
and policies of blocking appointments to the WTO's court and using tariffs as a national-security tool,
以及对WTO法庭约定的阻碍以及将关税用作是一种国家安全工具，
are inimical to an even-handed system that all can support.
都对一种所有国家都可以支持的公平体制怀有敌意。
Even if these policies turn out to be temporary, the uncertainty they cause may be permanent.
即便这些政策是暂时的，它们所引发的不确定性可能是永久性的。
Some of the USMCA's provisions go beyond even those of the TPP, for example its rules on the movement of data across borders.
USMCA中的一些规定远超TPP中的规定，例如，其对跨边界数据移动的规定。
And the USTR's objectives for talks with Japan, published on December 21st, are similar to those in the USMCA.
USTR于12月21日发布的和日本会谈的目标和USMCA中的那些相似。
But the fear is that, having all but abandoned the aim of broad trade liberalisation,
但人们担心除了抛弃广泛贸易自由化的目标，
America may prioritise quick, shallow deals rather than deeper ones that would strengthen global trade governance.
美国或许会给迅速肤浅的协议提供优先权，而怠慢那些能够巩固世界贸易管理的深入协议。
The complex "rules of origin" that feature in preferential deals are also worrying.
那些以特惠协议为特征的复杂的“原产地规则”也令人担忧。
These specify the minimum share of a product that must originate in the parties to a deal if it is to qualify for reduced duties.
这些协议规定一种产品的最小份额必须产自当事国所达成为协议才有资格享受减征关税。
They thus allow trade negotiators to shape supply chains and manage production.
因此，他们让贸易谈判代表制定供应链并管理生产。
And one study found that compliance costs amounted to 3-5% of the final product price, offsetting the deal's benefits.
并且一项研究发现税务执行费用总计为最终产品价格的3-5%，抵消了协议的收益。
The Trump administration has sought to use such rules to reshape car production in North America, tightening them by several notches in the USMCA.
特朗普政府寻求利用这种规则重新制定北美的汽车生产，通过USMCA中的几个等级加强对他们的控制。
As well as restricting trade, rather than liberalising it, they will make it tricky to agree more permissive rules of origin for cars in future trade deals.
和限制贸易一样，他们不会将其自由化，而是让它变得棘手从而无法在以后的汽车贸易协议中实施更加宽松的原产地规则。
It will soon become clear how ambitious America wants to be.
很快就能知道美国有多么的野心勃勃。
A deal with China that limited industrial subsidies, long a bugbear of other countries, could yet be baked into the multilateral system.
和中国的一项协议限制了工业补贴，这是长期困扰其他国家的一个难题，而这项协议可能会被纳入多边体制中。
One with Japan could set some useful standards and precedents.
和日本的一项协议可以设立一些有效的标准和判例。
Mr Trump may decide to blow up the multilateral system and impose tariffs on America's allies.
特朗普可能决定要摧毁多边体系并对美国的盟友施加关税。
Even if he does not, success on his terms could cause longlasting damage.
即使他不这么做，成功连任可能会导致持久破坏。

来源：经济学人