Nowhere did the slogan “take back control” resound more enthusiastically than in the ears of Tory free marketeers, who imagined themselves as modernist privateers, latter-day descendants of the proud tradition of Francis Drake and Walter Raleigh. During the referendum campaign you could almost hear them slapping their leather-clad thighs and looking eagerly ahead to a world where bluster and bravado replace the musty domain of the rule book and the bureaucrat.

Sadly, for these modern-day pirates of the high seas, trade in the 21st century is hedged by rules and restrictions, tariffs and quotas. Ruling the waves is going to require at least as much negotiation as finding our way out of the EU labyrinth. The events of the past few weeks have started to burst the Ripping Yarns bubble and brought the discussion down to Earth.

The first myth was that German manufacturers would put pressure on Angela Merkel to allow the UK to cherry-pick access to the single market without accepting freedom of movement. This has been demolished in a series of steps beginning with the German Employers’ Federation who made clear that the integrity of the single market came ahead of business deals with the UK. Now the Federation of German Industries is warning that German companies with a presence in Britain must “make provisions for a very hard exit”, because the British government doesn’t know what it wants. Perhaps we can turn the 95 production sites of German cars in the UK to innovative jam and biscuit factories. It is clear that Germany industry stands with the German government in placing political stability above narrow economic self-interest.

Before the shock and magnitude of the leave vote had really sunk in, Theresa May was jetting off to the US to hold hands with Donald Trump to beg him for a trade deal. He agreed, apparently with great enthusiasm. “We could have a really, really good trade deal,” he confirmed by Twitter. Great news to Brexiteers still euphoric at the result they had just pulled off. The problem is that Trump didn’t say who this deal would be good for, although the clue is in his campaign slogan: America First. Further information can be found in his book The Art of the Deal, wherein he explains that you always make a deal with your opposite number when they are vulnerable because this allows you to win by making them lose.

What this means in practice was made clear by the US’s decision to impose a 219% import tariff on Bombardier aircraft parts, jeopardising thousands of jobs on this side of the pond. These punitive tariffs are in response to what the US considers anti-competitive subsidies, an argument that we are likely to hear a lot more of in connection with our farmers in the competitive world of global trade.

While Liam Fox may be seeking to Make Britain Great Again, Trump is seeking to Make America Great Again. It is precisely because we learned that nationalistic competition on trade tended to make everybody poorer that we became engaged in trade negotiations in the first place.

This last week has also burst the bubble of the idea that the Commonwealth will be our salvation, a fantasy arising from too much public school education. A rare early agreement between the UK and EU was over the terms of our solo entry into the World Trade Organisation. This body is the dread of a free trader, with its complex system of tariffs, quotas and schedules, all of which have to be unanimously agreed by 164 member states.

The EU’s suggestion that the UK simply inherits its fair share of EU quota on the same terms was instantly rejected by a group of WTO members including Canada and New Zealand. Predictably, Commonwealth countries will be fighting for national interest rather than helping out the former colonial power in distress. Their economies were severely damaged by our shift in trade focus to the EU 40 years ago and they have moved on to find trade partnerships within their own regions.

This leaves only one strategy still available: the ignominious role as the world’s leading arms exporter, which helps to explain why half the secondments to Fox’s trade department are from arms manufacturers. It also helps to explain recent visits by May or Fox to Saudi Arabia, Turkey and the Philippines.

Then there is the proposal that we might join the Trans-Pacific Partnership (TPP), a trade deal with 12 countries bordering the Pacific Ocean. Our only geographical tie to TPP countries now is Pitcairn island, famous as the refuge of the Bounty mutineers. The symbolism of a bunch of renegades who reject existing rules and norms and find themselves isolated on a barren island could not be more appropriate.

• Molly Scott Cato MEP is Green MEP for the South West and Green party speaker on Brexit