The Hague Convention in particular states that drifting mines must render themselves safe after no more than one hour adrift and moored mines must render safe if they break loose from their mooring. In general, mines, like other classes of weapon, must not be used in indiscriminate attacks on civilians and/or neutrals: this often means that if you lay a field of mines you have to announce where it is.

Unfortunately, however, these rules only apply to us. None of our adversaries, potential or actual, cares one jot for them. Russia didn’t sign up to the Hague Convention and is highly unlikely to accept the Chatham House notion that it has “acquired the status of customary international law thus making it binding on all states”. Enemies like Iran and Russia deploy mines freely, including purpose-designed long lived drifters, deny they’ve done it, and then watch the results come in from a safe distance.

Now we get to the second issue with mines: how difficult it is to clear them. Some navies, particularly European ones, have effective MCM forces, but many do not. This is one of the areas in which the US is surprisingly weak: the US Navy doesn’t like dedicated minehunting ships and institutionally would much prefer it if MCM could be done using something more fun. Historically the USN has tried to do minehunting with helicopters and with trained dolphins: neither method works very well. It did reluctantly get a few minehunting ships back in the 1990s, but is now planning to retire them and make MCM an occasional, part-time mission for its unhappy Littoral Combat Ships.

Britain until recently could claim to be second to none in MCM with a decent-sized force of highly capable minehunters, able to detect mines using specialised sonar and deal with them using remote-operated systems or divers. The divers were also useful for retrieving the remote systems when they went wrong, among various other tasks.

Now, however, we Brits have succumbed to a variation on the American disease and are getting rid of all our minehunters in favour of remotely operated long-ranging surface and underwater drone systems. These will be based aboard civilian “motherships” cheaply purchased from the offshore industry and crewed by the Royal Fleet Auxiliary rather than the Royal Navy itself. This is being done primarily to save money, rather than for any other reason.

The first mothership, RFA Stirling Castle, has already been bought in but she isn’t ready to use, and if emerging reports are to be believed, she might never be. It will certainly be a long time until the RFA, currently in a manpower death spiral, will be able to find a crew for her.

Meanwhile we are giving away several of our retired Royal Navy minehunters, tried and tested assets which actually work, to the Romanians and Ukrainians. They’ll be very useful as and when the Turks decide to let them through the Bosporus.

Once again, crushing long-term financial restrictions have backed the Royal Navy into a corner. The Service is busily talking up the importance of seabed warfare whilst giving away the assets that are best at doing it. 

Even if you have ample, effective MCM forces there are two realities in clearing sea mines: it takes a long time, and you can never be sure you’ve got them all – all you can do is provide a reduced level of statistical risk in a given area or corridor. The larger the area and the lower the risk desired, the longer it takes – with the time required rising exponentially as you approach complete safety.

If you find and have to dispose of large numbers of mines while clearing your corridor the time goes up even more. And if illegal long-lived drifting mines are present, a clear corridor one day does not carry over to the next. Mines on land are dangerous too but at least there, once you have cleared an area, it remains cleared. At sea, this is not the case. 

So far in the Black Sea mine strikes have been mercifully rare. The MV Helt, an Estonian cargo ship, was hit and sunk off Odesa in March 2022. All six crew escaped unhurt. The fact that she was hit at anchor suggests it was a free-floating mine. The bulk carrier Vyssos was hit near the stern while en route to the Izmail port on the Danube. The captain’s rapid decision to deliberately ground the ship has been credited with saving it from sinking.

To try and counter this, Turkey, Romania and Bulgaria signed a memorandum of understanding in Istanbul establishing the Mine Countermeasures Naval Group in the Black Sea (MCM Black Sea) but the size of the grain corridor (310 nautical miles long) presents a huge challenge even for this combined MCM effort. 

Russia has a number of military ways of launching mines in the Black Sea, from their Kilo-class submarines to their warships to aircraft and helicopters. Given how beleaguered Russia’s Black Sea Fleet currently is, driven further and further east by Ukraine’s innovative and imaginative use of sea drones, Russia’s ability to use these options is currently limited. But the problem with mine laying is that almost any vessel can do it. Iran specialises in fishing vessels with barrels on the back that open up to reveal mines and a rail from which they can be launched. Such methods are hard to detect and largely deniable.

As one US admiral, having trouble with enemy mines, remarked during the Korean War:

“We have lost control of the seas to a nation without a Navy, using pre-World War I weapons, laid by vessels that were in use at the time of the birth of Christ.”

Russia’s Black Sea mining campaign is not just a war crime: it isn’t just a vicious attempt at weaponising starvation by cutting off one of the world’s major suppliers of grain, though it is both those things. Putin’s sea mining campaign also runs the risk of triggering a direct war with Nato. Turkey, Bulgaria and Romania are all Nato nations, and the grain corridor lies within their territorial waters: not their much larger Exclusive Economic Zones, but their actual maritime territory, inside the 12-mile limit. On September 11 the bulk carrier Aya was hit by a Russian missile inside Romania’s EEZ, but this is not an act of war against Romania (and thus Nato): it is merely a war crime committed on the high seas.

The point is, what happens when a free-floating mine drifts into Nato territorial waters and sinks or damages a ship there? That is a Nato Article V situation: the alliance members are required to respond to such an attack as if it were an attack on them all. This is why rules are in place to control the use of mines and why it is so dangerous when they are ignored.

Sending retired Sandown-class minehunters to both Romania and Ukraine undoubtedly forms a major part of the solution for them (once the ships are allowed into the Black Sea) but it does raise a question: what we should donate versus what we need to keep for ourselves while our own new Mine Hunting Capability (MHC) programme matures. I’m not pretending this isn’t a complex dilemma but am pretty sure that the cross-Whitehall system to accurately prioritise what we need across defence and then decide what we give away is not in place. 

Mine warfare will be relevant forever and freedom of navigation will always depend on being able to conduct effective MCM. It is a live threat in the Black Sea today and due to its indiscriminate nature, it’s only a matter of time before Russian mining causes a major incident which could escalate.

The solution is unglamorous, technical, time-consuming and expensive. It needs more resources allocated to it, not less, both here and abroad. 

Tom Sharpe is a former Royal Navy officer