WHEN white supremacists in the landlocked British colony of Rhodesia unilaterally declared independence in 1965, Harold Wilson’s Labour government responded with a ban on the supply of oil to the country’s sole refinery.

This was enforced by old school imperialist gunboat diplomacy, with the Royal Navy intercepting suspect tankers bound for Beira in Mozambique, having secured a United Nations mandate to do so.

For those shipowners with no moral qualms about taking the charters anyway, there were straightforward workarounds. The easiest of them was to discharge crude in South Africa, with the apartheid regime pumping it on to their beleaguered fellow racists via a pipeline.

Shell and BP — in what cannot be the proudest chapter in their long histories — stayed with the letter of the law by coming to a swap arrangement with Total.

The French oil major sold oil to Salisbury, as Harare was then known. The British companies then sold Total the equivalent amount, and everybody went home happy. None of this was actually illegal.

Those were more innocent times. The oil export price cap on Russia will not be so blatantly circumvented. Then again, the rules have been purposely designed to provide so much leeway that they won’t have to be.

Essentially, the mechanism represents an elaborate obstacle course that tanker operators and marine insurers can just about finish. But will simply getting lawyered up will be enough to keep them on the straight and narrow? Perhaps not.

In a world where “compliance” is an ever-growing concern for big business, it is glaringly obvious that shipping is behind the curve.

Citibank, for instance, now employs a staggering 30,000 staff worldwide with the sole remit of ensuring the bank does not fall foul of the proliferation of stipulations imposed by an expanding roster of regulators.

While larger shipping companies will have dedicated compliance professionals on their payroll, with talk that the discipline is seeing greater demand from industry middleweights, some smaller ones may not.

Sanctions are not going away any time soon, as two experts in the field tell this week’s Lloyd’s List Podcast.

Agathe Demarais, author of the recent book Backfire: How Sanctions Reshape the World Against US Interests, contends that it doesn’t much matter whether sanctions ‘work’ or not.

Wilson’s oil embargo did not stop Rhodesia getting its hands on oil. Nor, alas, will the price cap on Russian crude and products do much to speed up Kremlin withdrawal from Ukraine.

The attraction for politicians is instead a cheap quick “something must be done” fix that splits the difference between endless rounds of futile talking shops with uncompromising interlocutors and putting boots on the ground.

Ms Demarais’ case is that sanctions are rapidly becoming the international relations equivalent of antibiotics. Once the miracle cure for many diseases, their administration can be rendered futile by widespread overuse.

Reed Smith partner Leigh Hansson points out that sanctions are now been issued in unprecedented volume. Even sanctions lawyers a struggling to keep up, she admits, which is an astonishingly frank thing for a sanctions lawyer to say.

To add to the complications, sanctions are no longer purely a Western prerogative. The system is fragmenting before our eyes.

China is increasingly assertive on the world stage and introducing sanctions in support of its foreign policy goals.

Iran has issued counter-sanctions to those levelled at Tehran, which some fear could threaten freedom of navigation in the Middle East Gulf if the bite matches the bark.

The situation adds up to a monster hangover-sized headache, and pleas of “I’m just a simple shipowner, all this world politics stuff is above my paygrade” are unlikely to be heeded.

In the Russian case, marine insurers at least have a defence of attestation. If owners and cargo interests tell them the cap has been met, they are entitled to believe them.

How to handle the section of the industry for whom their word is not always their bond will be an interesting judgement call.

According to Wilson’s most recent biographer, the prime minister probably wasn’t aware of Shell and BP’s subterfuge at the time. But at least two of his cabinet ministers were, and chose to turn a blind eye.

It would be unwise to count on similar connivance from the top in the twenty-first century. Ask BNP Paribas, which was hit with an $8.9bn fine for breaching sanctions against Iran, Cuba and South Sudan.

The Russian price cap will either prove so lax that no shipowner will need to break it, or tough enough to see someone eventually get caught red handed. We shall soon find out which.

But heaven help those who try to stay just within the rules and somehow find themselves just outside them.