Someone has to do it, so I will. This policy is holed below the waterline before it begins. Zia Yusuf wants Britain’s warships to push migrant boats back to France. There are only three small problems: the law, the French and the Royal Navy. Operation Fortress will be “the largest military operation in the English Channel since World War Two”. Nigel Farage will grandiosely order “his Majesty’s Royal Navy” to intercept every unauthorised vessel crossing the Channel and return its occupants to France. No one arriving illegally will reach Britain. The border will become “impenetrable”. The invasion will be stopped. It sounds magnificent, provided you know nothing about ships, sailors, France or the law. The first clue lies in the name. Operation Fortress sounds like the title of a 1960s war film. Once the bunting has been cleared away, this new policy amounts to parking a few warships in the Channel and instructing them to make the small boats go backwards. Nobody appears to have asked what happens when they do not. An overloaded inflatable carrying 60 or 70 people is rather different to a French fishing trawler whose skipper can be ordered to head for Calais. It may have insufficient fuel, an inadequate engine, and no one aboard capable of navigating it safely. The smugglers may have left the controls in the hands of one of the passengers. The boat may already be leaking, listing, or taking on water. A Royal Navy officer cannot order an inflatable to become seaworthy. The Navy cannot legally fire across its bow. This is a border control operation, not a war. There may not even be enough bow to fire across. HMS Cottrell cannot ram the boat, create a wash beside it or undertake aggressive manoeuvres without risking a capsize. Sending a boarding party alongside an overcrowded dinghy creates another opportunity for dozens of frightened people to shift their weight at once and end up in the water. The moment the boat becomes unsafe, Nigel's great military operation turns into a rescue mission. British sailors are legally required to save those aboard. The obligation arises under the law of the sea, the International Convention for the Safety of Life at Sea and the International Convention on Maritime Search and Rescue. None of these contains a Zia Yusuf exemption. After rescuing the passengers, the Navy must take them to a place of safety. Reform says that place will be France. France may have something to say about that. Britain cannot sail warships into French territorial waters, seize boats, or disembark passengers in Calais without French permission. Nor can it deposit 70 people at the maritime boundary and invite them to swim the remaining distance. Returning them to France requires the French government to accept them. This is the gap at the centre of the policy. A Reform government can give orders to the Royal Navy; it cannot give orders to Emmanuel Macron. There is already a UK-France returns agreement. It permits selected small-boat arrivals to be returned after they reach Britain, in exchange for Britain accepting an equivalent number via a legal route. The arrangement exists because France’s consent is required. It is limited, negotiated and reciprocal. Nothing in it authorises the Royal Navy to deliver every intercepted passenger to a French port. Perhaps Reform has secretly negotiated a much broader agreement with Paris. Perhaps Macron has promised Farage that France will accept tens of thousands of people in exchange for nothing. Perhaps the French will also provide a complimentary cheese board. The details, we are told, will be revealed today. Without French agreement, the Navy will intercept the boats, rescue their occupants, and bring them to Britain. Reform’s answer to the “free ferry service” is to paint the ferry grey and staff it with sailors. The legal problems persist after rescue. Once British forces exercise effective control over a boat or take its passengers aboard, those people fall within British jurisdiction. They cannot all be summarily expelled without any examination of their circumstances. France is a safe country, and there is no general legal prohibition on returning an asylum seeker there. However, any return must still take place under a lawful arrangement. Officials would need to identify children, trafficking victims, those requiring medical treatment, and anyone presenting a specific reason why return would expose them to serious harm. Roughly one in seven small boat arrivals since 2018 has been referred to the National Referral Mechanism as a possible victim of modern slavery. Among those who arrived in 2025, the eventual figure reached 19 per cent. Those cases cannot be resolved by a sub-lieutenant circling boxes on a clipboard while HMS Harborne bobs around somewhere off Dungeness. The European Court of Human Rights has already held that intercepting migrants at sea does not create a legal black hole. In Hirsi Jamaa v Italy, Italy was found to have violated the European Convention by returning intercepted migrants without considering their individual circumstances. In that case, the destination was Libya, so it does not establish that returning to France would be unlawful. It does establish that a government cannot evade its obligations by processing the entire group under the legal category of “off you go”. Reform might respond that it intends to leave the European Convention. That still leaves the Refugee Convention, maritime rescue law, France’s sovereignty, and the stubborn tendency of drowning people to require rescue. A press conference cannot repeal the sea. Then there is the Royal Navy itself. Britain possessed 32 frigates and destroyers in 2000. By October 2025, it had 14. Several of those were undergoing maintenance or preparing for operations. The Navy is also attempting to sustain the nuclear deterrent, protect two aircraft carriers, patrol the North Atlantic, support NATO, guard undersea infrastructure, maintain overseas deployments, and prepare for a possible war with a serious state adversary. Amid this crowded programme, Zia Yusuf demands the largest Channel operation since 1945. A Type 45 destroyer is a £1 billion air-defence platform designed to protect a carrier group against missiles and aircraft. It carries sophisticated radar, anti-aircraft weapons and a crew of nearly 200. Using one to chase inflatables off Dover would be rather like sending a new Challenger 3 tank to enforce parking restrictions outside Lidl. The Type 23 frigates are old, scarce and already stretched. The River-class offshore patrol vessels are better suited to maritime security, but the newer ships have global commitments, while the older ones perform fisheries protection, patrol and training tasks. Moving them into the Channel simply leaves gaps elsewhere. Border Force operates five cutters, six coastal patrol vessels and a range of smaller craft. These are the vessels designed for customs and immigration enforcement. Even that fleet cannot create an impermeable cordon while covering Britain’s other maritime borders. The Channel is one of the busiest shipping routes on earth, not a village pond across which the Royal Navy can stretch a chain. Ships also require crews. As of April 2026, the Royal Navy and UK Marines had 32,520 regular personnel, of whom 4,580 were untrained. Recruitment has begun to improve, but the Navy remains critically short of experienced technicians, engineers and specialists. Some vessels have been alongside for extended periods because the service lacks the trained personnel to operate them. A continuous patrol requires several crews for each vessel on station. One crew is at sea, while others are training, recovering, taking leave or preparing the ship. Each interception requires qualified boat crews, boarding parties, medics, communications staff and command support. If people are brought aboard, the ship also needs space, food, sanitation, interpreters and safeguarding personnel. Warships do not come with infinite sailors. The smugglers would adapt before the first triumphant press release had even finished circulating. They would overload boats until turning them around became impossibly dangerous. Engines would “fail” as British vessels approached. Passengers would be instructed to call for rescue, enter the water, or threaten self-harm. Several boats would launch simultaneously during brief windows of good weather. The absolute promise that nobody will reach Britain creates an incentive to treat every encounter as a humanitarian emergency. The Navy would either rescue those aboard or preside over preventable deaths within sight of its ships. No commanding officer should be placed between his legal duty to save life and a politician’s promise that not one migrant will set foot on British soil. There are serious policy options available. Britain could negotiate broader returns with France, fund aggressive French interception near the beaches, attack the financial and logistical networks behind the crossings, accelerate asylum decisions, remove failed claimants, and build a Border Force fleet capable of sustained maritime enforcement. Joint patrols could operate under an agreement that defines jurisdiction, disembarkation, and responsibility for rescued individuals. Operation Fortress contains none of the difficult parts. France will apparently accept everyone. Every boat will turn around safely. Every legal claim will disappear. The Navy will find spare ships and sailors somewhere in a cupboard in Portsmouth. Declaring the Channel impenetrable will make it so. This is not a serious or credible policy. Operation Fortress is nothing but a press release wearing a sailor’s hat.