The British and French standoff on the seas round Jersey is, at first glance, a row over logbooks, lobsters, licences and sea snails.
But it is the result of a perfect storm of British, French and European politics and, inevitably, Brexit.
The technicalities of fishing licences in the 12 miles around Jersey’s coasts are vitally important for French fishermen.
They blockaded Jersey’s main port, after accusing the Channel Island government of not granting enough licences and imposing unfair conditions on them.
But such disputes rarely lead to Royal Navy and French navy ships eyeing each other across the waves unless it suits politicians on both sides.
So how did it come to this? The UK-EU Trade and Cooperation Agreement (TCA), which came into force on December 31 last year, sets out the new post-Brexit fishing rules.
Under the deal struck on Christmas Eve, EU boats can continue to operate in UK territorial waters if they can prove historical fishing activity in the area.
Access is granted by the issuing of fishing licences but France is angry about how the new rules are being implemented and has accused Britain of dragging its feet.
Larger French boats with positioning technology have been granted licences, but smaller boats do not typically carry the electronic equipment that would allow them to prove they fished the UK’s coast from 2012-2016.
In late April, French fishermen blockaded ports to prevent UK-landed fish arriving in Europe in protest. UK-EU talks are continuing to agree on an alternative way of proving past fishing activity.
While this continues to be an issue in the waters around Jersey, the situation is more complicated.
Jersey is a self-governing British Crown Dependency. It has responsibility for its own fishing rules but can, as it did in this row, call on UK assistance.
However, the UK is responsible for Jersey’s international relations; the Channel Island is bound by the TCA negotiated by London and Brussels, and so are the French.
France and the European Commission have accused the Jersey government of adding new unilateral conditions on top of the requirement to prove historical fishing activity.
These include restrictions on where in the waters the boats can fish, for how long and with what machinery.
Paris brands this “unacceptable”, and Brussels says it breaks TCA rules that require such conditions to be pre-notified, and shared by local fishermen as well as EU ones.
British sources indicate that the decision on rules for Jersey’s water is the island’s responsibility, but Brussels is determined to place the issue firmly on Boris Johnson’s lap, and deal with it at UK-EU level.
Downing Street sources insist that Jersey has acted within the rules of the TCA, even if the government has not imposed the same conditions on French boats in the UK’s territorial waters.
Whether Jersey’s government sticks to its guns remains to be seen, but there are discussions about finding “wriggle room” in the restrictions, which suggests the pressure is beginning to tell.
Regardless of the end result, the timing of this latest battle with Brussels and the French is good for Mr Johnson.
On the day of local elections, the Prime Minister can bask in the glory of phony war which will do the Conservatives no harm at all.
With elections in Scotland, a disheartened Scottish fishing industry and the independence debate in full swing, the timing is perfect to show that Mr Johnson is willing to fight for “our” fishermen.
A demonstration of Global Britain ruling the waves may go some way to repairing the damage of the Brexit talks, which left UK fishermen convinced the Prime Minister had betrayed them at the last.
“Boris has found his Falklands,” one EU diplomat joked shortly before the French fishermen left just before lunchtime.
Emmanuel Macron also knows the value of a good fight. French fishermen are furious with their president after their share of the catch in UK waters was cut in the Brexit negotiations.
Their anger has mounted because they believe Britain is dragging its feet in granting fishing licences.
As in Britain, fishermen represent a small sliver of the economy but carry a huge political and emotional weight. It is said that when French fishermen move, the government trembles.
Another consideration is that French fishermen in the Channel hail from Northern France, which is a stronghold for Marine Le Pen.
Ms Le Pen will be Mr Macron’s main rival in next year’s presidential elections. No one expects her to beat Mr Macron but she will make it to the second round of the presidential elections and with increased support from the last elections.
Ms Le Pen will only benefit from this contretemps, and Mr Macron must be seen to do something.
Perhaps this is why he dispatched a small portion of the fleet, and why his Minister of the Sea threatened to cut off Jersey’s power supply. That dramatic threat has also been criticised in some British quarters as breaching the rules of the TCA.
The early days of the new Brexit arrangements have been rocky and turbulent. That was always to be expected so soon after the divorce, but UK-EU relations have been particularly bad.
The implementation of the Northern Ireland Protocol was always going to be controversial, but Britain stands accused of breaking international law for the second time in a matter of months.
The European Commission’s hysterical over-reaction to the UK’s vaccination success and AstraZeneca’s supply failure was to threaten a vaccine export ban against Britain and to impose a hard border on the island of Ireland.
The wounds of Brexit are still raw, and the temptation to exploit teething problems for short term political gain remains for the UK, France and the European Commission.
The imperative is still there for the EU to prove that Brexit was a historical mistake which no member state should ever dream of repeating.
And there is also pressure on the British Government to prove that the freedoms won by Brexit will prove to be worth the economic cost in trade friction with the EU, which remains the UK’s major trading partner.
But there is also an incentive for both the UK and the EU to get the trade deal working properly, and without such tension.
There were, until recently, signs of detente after the European Parliament ratified the Brexit trade deal in April. The UK finally agreed to give the EU’s ambassador in London full diplomatic credentials shortly afterwards.
The row over Jersey looks set to be funnelled into the dispute resolution process in the trade deal.
That is likely to mean discussions, and lots of them, in meeting with EU officials in the bloodless committee rooms of Brussels and London that are the first port of call in any dispute.
While any persisting row could ultimately result in tariffs, a compromise is far more likely to be quietly found.
The political capital of the hijinks on the high seas will be safely pocketed by then – and the perfect storm of the so-called “war with France” will be kept firmly in its teacup.