I’m not sure why you think being part of NAFTA, a free trade agreement, is equivalent to being an EU member and thus accepting law from a supra state, you’d have to explain that.

* Sovereignty is not a binary concept - it is not the case that you either have 1 or 0 sovereignty.

* The geopolitical game is not a zero sum game.

Both observations are trivial and I am surprised that they need to be stated here at all.

Canada choose to amend it's law [1] for the sole reason of complying with USMCA. Thus Canada sees the agreement a mutually beneficial (no zero sum). Canada "clearly yes" still a sovereign state so you seem to agree that sovereignty is not binary.

To remain in the game, UK will have to enter into trade agreements with other players and as a consequence enact compromises either in law or in policy. Immigration is a good example because 1. one of the stated benefits of leaving the EU is tighter control and reduction of immigration and 2. as a consequence of the need to negotiate with trade partners, it may very well need to relax those controls.

Finally note that UK was not forced to join the EU. It did so by choice as a sovereign state. While in EU, it was a major member of the club and could and did steer policy and legislation to suit it's own needs.

[1] https://www.jdsupra.com/legalnews/what-the-amendments-to-the...

> Canada "clearly yes" still a sovereign state so you seem to agree that sovereignty is not binary.

is not you pointing out something to me, nor likely anyone else but yourself.

> To remain in the game…

To that entire paragraph, again, I have to point out that it's irrelevant to the points being made against the statement “We do know the UK has kept its sovereignty”. It strikes me rather like someone who's trying to persuade an opponent by shifting their "gotcha" arguments as they are challenged and fall instead of sticking to the point, especially considering the decision to leave and leaving are done.

When you find a trade agreement that means another state will make law in the UK and have its law supreme, then you'll begin to have a relevant point about what's being given up for immigration or whatever. Keep in mind that bit about game theory, they have scoring systems ;-)

> Finally note that UK was not forced to join the EU. It did so by choice as a sovereign state.

And undermined its sovereignty to an enormous degree that actually threatened the constitution. From 22:31 of Vernon Bognador's talk[0] at Yale:

> When Harold Macmillan sought to join, he encountered fundamental difficulties, difficulties which probably have never been resolved, and the essence of the problem was one of fitting Britain into a continental system whose assumptions about constitutions, politics and economics was so different from those held in Britain.

> The most fundamental problem, perhaps, was that of fitting a constitutional system based on the sovereignty of parliament and the absence of a codified constitution into one based on a written constitution, the separation of powers, and subordination of the legal systems of the member states to superior system of European law.

Vernon Bognador is British Research Professor at the Institute for Contemporary British History at King's College London and Professor of Politics at the New College of the Humanities. He is also Emeritus Professor of Politics and Government at the University of Oxford and Emeritus Fellow of Brasenose College, Oxford, and has written several books on the British constitution and Brexit. He voted to remain in the EU[1].

And to this:

> While in EU, it was a major member of the club and could and did steer policy and legislation to suit it's own needs.

I want to underline, as I wrote above I'm not particularly interested in hackneyed arguments for remaining in the EU given that they are moot and not relevant, so I'd ask that you save them for your friends and try to keep to the point with future replies.

[0] https://www.youtube.com/watch?v=WMV9wSSLcCY

[1] https://www.telegraph.co.uk/politics/2019/10/10/second-refer...