President Trump likes to talk about “sovereignty” – he mentioned it 17 times in his address to the UN last autumn. He has denounced “open borders” and called for the construction of a wall on the US border with Mexico. He also questions trade agreements. He called Nafta, for example, “the worst agreement in history.” In Europe, self-styled “populists” also combine claims for protection of “sovereignty” with attacks on “global trade” or “open borders.”  

So it is easy to assume all these claims go together. In fact, the main thing they have in common is they all provoke and annoy Left-liberal advocates for a “globalising world”. That might be enough for campaign soundbites. It’s not enough to sustain a serious approach to real policy. 

Sovereignty is fundamentally about the right to make your own laws, not a compulsion to make laws about everything.

To start with, we should distinguish trade in goods from trade in people. Foreign-made goods will sit on a shelf until resold or used by particular owners. If you admit foreign people, they are part of your society – for better or worse, in one way or another. It’s perfectly rational to welcome the goods while being cautious about the people. There are lots of historic examples of trading states which took a very cautious approach to immigration, as Switzerland, for example, still does.

The larger point to remember is that sovereignty is fundamentally about the right to make your own laws, not a compulsion to make laws about everything. The term first became a theme of political writers in the 16th Century. It was aimed at restricting papal interventions into local political affairs and restricting feudal claims that cut across national borders. “Sovereign” power was identified with ultimate control of force, not total control of everything in a territory.

So the French jurist Jean Bodin, the first writer to make a theme of sovereignty (in his Six Livres de la Republique, 1576), offered a list of essential sovereign powers, including the collection of taxes, the coining of money, the regulation of weights and measures. He did not bother to include control of imports as an essential sovereign power. He endorsed cross-border trade.  

By the mid-18th Century, William Blackstone’s Commentaries on the Laws of England, noting that all government powers were ultimately governed by laws, taught that “sovereignty and legislature are convertible terms” because “one cannot subsist without the other”.

By the mid-18th Century, William Blackstone’s Commentaries on the Laws of England, noting that all government powers were ultimately governed by laws, taught that “sovereignty and legislature are convertible terms” because “one cannot subsist without the other”. When American colonists denied Parliament’s power to impose taxes on Americans, they proceeded quite rapidly to the conclusion that the colonies were entitled to regard themselves as independent states.

But one of the arguments colonial leaders advanced for independence was that the British government had abused its authority “by cutting off our trade with the rest of the world”. The same Congress that endorsed the Declaration of Independence (where this complaint appears) also proposed a model treaty for trade relations with outside countries, offering to treat imports on the same terms as domestic production if other states would do the same for American exports.   

At the time there were no takers for this American offer. Advocates for American tariffs often argued they were necessary to pressure foreign states into reducing their own obstacles to American imports (the Constitution adopted in 1788 forbids the US government to tax exports).   Still, when Britain acquired new colonies in Africa and Asia in the 19th Century, it imposed British law but left these places open to the trade of all nations (having learned a lesson from its disastrous experience in trying to restrict the trade of the American colonies).

A sovereign state retains the legal authority, of course, to restrict imports. There are always people who claim that is a good thing to do, because a nation should care more about the livelihood or well-being of its own producers than the foreign producers who compete with them. That might seem an irresistible argument, except that domestic consumers (and domestic producers using foreign materials) also have claims on their government’s protection.  

You can think national solidarity is important without concluding that citizens should deal only with each other in trade. Few people think that family loyalty requires all siblings and cousins to work on the same farm or work for the same firm: if they did, they’d likely have much less wealth and more occasion to bicker with each other over how to divide their common profits.

If you value national sovereignty, you should be sceptical of systems that relegate more decisions to distant bureaucracies. That’s true even if you call yourself a populist. Maybe especially so.

Here’s a related challenge for would-be populists to consider. Most governments don’t try to control too much of the domestic economy, because it is too hard to anticipate what controls will prove effective over time and which may do more harm than good. 

Still, modern states aspire to regulate more than their national parliaments can foresee, so they delegate a lot of authority to specialised bureaucracies. John O’Sullivan, the peripatetic commentator of the Anglosphere, recently offered a “definition” of “populism” as “the democratic response to bureaucratic rules (and rule)”.

That concern should apply with special force to transnational bureaucratic authority, because it is so little accountable to elected legislatures. But if you are too ambitious for precisely targeted trade controls, you have to rely on bureaucracies to calibrate and recalibrate them. Long before the European Union, the six-nation European Coal and Steel Community of the 1950s already had established a specialised commission to determine proper exceptions, adjustments and revisions to the otherwise agreed rules on free passage of coal, iron-ore and steel among the member states. Only the European trade arrangements have delegated so much authority to specialised bureaucracies to make rules for the members.  

Similarly, if your aim is not just to reduce barriers to trade, but to achieve a certain pattern of trade flows, you can’t just get member states to agree on trade terms among themselves. You will want to restrict the trade agreements they make with other nations – as the EU now does. Neither Nafta nor other regional agreements impose such restrictions on members. They are not so ambitious. Here, as elsewhere, the EU has taken a power that was previously in the hands of sovereign states and handed it off to specialised bureaucracy.

None of this proves that the most open trade regime will always be the most popular or advantageous. But part of the point of sovereignty is that it gives a nation the chance to change its laws – to adapt. That’s the virtue of open economies, too. They give citizens and firms more opportunity to adapt to changing circumstances. If you value national sovereignty, you should be sceptical of systems that relegate more decisions to distant bureaucracies. That’s true even if you call yourself a populist. Maybe especially so.