At the end of May, a ship named the Christophe de Margerie slipped out of Utrenneye, a port on the flat, treeless Siberian coast of the Kara Sea in the Arctic. At 299 metres – roughly the length of three football pitches – the large ship is named after a French oil executive who was killed in a freak accident at Moscow’s Vnukovo Airport in 2014.

She is a liquefied natural gas carrier (LNG) whose insulated tanks can hold more than 170,000 cubic metres of gas.

The Christophe de Margerie is an icebreaker too: it has a reinforced double hull and three independently rotating propulsion units that allow the ship to force its way through ice more than two metres thick.

These are essential to use remote terminals – such as Utrenneye – that conventional carriers cannot reach for much of the year.

The ship sailed east after it had loaded, escorted along the coast by a Russian nuclear-powered icebreaker.

According to ship-tracking data, on June 8 it passed through the Bering Strait before continuing on to a floating storage unit off the Kamchatka peninsula to deposit its cargo – almost certainly for onward delivery to China.

It was not the first time that the ship has made the journey along what is usually referred to as the Northern Sea route, but it is the first time a commercial vessel is known to have done so this early in the year: until June, the ice is normally too thick to contemplate such a voyage.

A major reorganisation of the world’s climate is not just leading to unusually warm summers in Britain; it is also leading to geopolitical changes that are having – and will have – enormous implications for trade routes, for the global economy and for national security.

Last week, Donald Trump effectively declared Greenland a blank canvas for American territorial expansion.

He signed an agreement with Denmark that apparently grants the US total control over Greenland’s security, meaning the US can now build new military bases there ‘as needed’ according to Fox News.

Whether the American President’s braggadocio survives publication of the deal’s fine print remains to be seen, for Danish commentators have been quick to point out that America has long had a free military hand in Greenland.

But Trump’s covetousness of the Arctic island isn’t misplaced, as over the next few decades the barren, ice-covered reaches of the High North are set to become a geopolitical crucible of vital trade routes, military brawn and superpower rivalry. To that end, the Christophe de Margerie’s passage last May was an arguably far more significant development.

For centuries, the idea of a northern short cut to Asia pre-occupied and fascinated sailors. The twin discoveries of routes across the Atlantic and around the southern tip of Africa into the Indian Ocean in the 1490s had opened up new geographies and opportunities, paving the way for trade to become truly global.

Although the discovery of the Americas had extraordinary consequences, it was the routes to Asia that were more rewarding. Then, as now, Asia was home to large populations, wealthy cities and riches waiting to be tapped.

Until the early 1500s, trade had reached Europe through networks that have come to be called the Silk Roads – land and maritime connections that wove peoples together from China and India through the Middle East and East Africa.

The main beneficiary was Venice, whose wealth allowed the greatest families to build magnificent palaces rising out of the lagoon at the northern end of the Adriatic Sea.

For those in northern and western Europe, finding the quickest way to Asia was important, both for speed but also for security: the journey round Africa and the Cape of Good Hope was long and could be treacherous – and furthermore involved sailing close to Spain and Portugal, whose ships dominated the Atlantic, at least initially.

By the 1550s, English expeditions were attempting to find a route through the northeast passage – skirting the northern coast of Scandinavia, into Russian waters and beyond to the Far East. They were followed by the Dutch whose merchants were determined to find new ways to reach Asian markets.

Willem Barents went furthest, reaching Novaya Zemlya – the vast archipelago in the far north, beyond Scandinavia, considered the easternmost point of Europe – in 1596. His ship got trapped and ultimately crushed by ice as the seas froze in the winter. Barents and his crew survived over the bitterly cold months that followed, building a makeshift hut from timber and other materials they salvaged from their ship – only to die from sickness on his attempt to reach home the following year. The body of water that lies at the western gateway to the Arctic still bears his name: the Barents Sea.

Other attempts fared little better, with the first successful transit not happening until the 1870s when the Finnish-Swedish aristocrat Erik Nordenskjold sailed eastwards, almost reaching the Bering Strait before ice closed around his vessel, the Vega.

Its specially reinforced hull survived the pressure and remained trapped for almost 11 months before the ice melted and the ship continued on, through the strait and down Russia’s Far East coast to Yokohama in Japan. It was the first successful navigation of the Northern Sea route.

Three things have changed today. First, improved technologies mean that ships – such as the Christophe de Margerie – can now push their way through ice during the summer months with relative ease. Second, warming conditions mean that ice is thinner and more broken up; indeed, some stretches are now increasingly ice-free for long durations in the summer.

Although there is some discussion about future projections, the UN’s Intergovernmental Panel on Climate Change suggests that the Arctic Ocean will experience its first practically ice-free summer by 2050. One recent study suggested this will happen as early as the 2030s given current warming patterns. This has major implications for shipping and trade.

Since the early 1990s, much of global manufacturing has moved to China, powering a period of astonishing growth and rising ambition. For those who buy

Chinese-made goods in Europe, the Northern Sea route promises quicker deliveries and lower prices: a journey from Shanghai to Felixstowe currently involves 11,000 miles and takes 35 days – involving a long route across the Indian Ocean, through the Suez

Canal and then transiting the Strait of Gibraltar.

The new northern route is much shorter: last year, Spirit of Istanbul sailed from Ningbo to Felixstowe in just 21 days on a journey almost 30 per cent shorter at just 8,000 miles. That means a quicker turn-around; it also means less fuel. Both mean reduced costs and better returns on capital.

But the Northern Sea route is not just about savings and profits. It is also a key part of a major reconfiguration that involves the world’s sea lanes, its trading patterns and changing priorities.

In 2005, Yang Huigen, one of China’s leading polar scientists, gave an interview in which he said that the country should aspire to become a ‘polar great power’. It is an ambition that China has pursued with gusto for more than two decades, championed by President Xi Jinping personally who has spoken repeatedly about the importance of the Arctic and Antarctic capabilities. Regular policy papers have stated that the polar regions – together with the seabed and outer space – are ‘strategic frontiers’ that have vital consequences for the country’s place in the world of the 21st century.

Such has been the investment of time, resources and planning that in 2018 China declared that it was a ‘near-Arctic state’, despite the most northern part of the country lying almost 1,000 miles south of the Arctic Circle.

This is a statement of intent more than an indication of territorial ambitions, underpinned in the first instance by the desire to be included in policy decisions and discussions of any international agreements that may have a major impact on China’s economic growth, its political stability and its military posture.

That in turn matters since, as events in other parts of the world have shown, the Northern Sea route is not just about shorter journey times or lower costs but about having options that are as essential as they are valuable.

Since 1869, the fastest way to move between Europe and Asia has been to transit the Suez Canal, a waterway around 120 miles long that saves ships from making the long journey around Africa. The canal – like the Bab al-Mandeb at the mouth of the Red Sea that links to the Indian Ocean – is one of the world’s great shipping routes.

Both are places where relatively minor disruptions can throttle the movement of ships and their cargoes. Their vulnerability makes them obvious pressure points for states, armed groups or terrorists seeking political leverage, ransom payments or demonstrations of power that bring attention to their cause both regionally and beyond.

For the past three years, the Houthis – an armed insurgent group closely aligned with Iran – have severely disrupted shipping going through the Red Sea, by threatening, seizing and attacking commercial vessels.

As well as pushing up insurance premiums, that has also led to a host of shipping companies avoiding this region altogether.

Taken with the effective closure of the Strait of Hormuz, a key chokepoint since the US attacks on Iran in February, the need for alternative routes could not be more obvious.

This too raises the significance of the Northern Passage. So far, the number of ships taking this route remains modest, with around 100 vessels reported to have done so last year. But that number will rise in the future. As it does so, it presents commercial opportunities. It also presents challenges and concerns.

In December, the Royal Navy unveiled Atlantic Bastion, a programme combining ships and patrol aircraft with autonomous vessels and underwater sensors to track Russian submarines across the North Atlantic in what senior officers reminded was a return to familiar anxieties about the formidable challenges posed by the Soviet Union’s Northern Fleet during the Cold War.

Just last week, the First Sea Lord, Sir Gwyn Jenkins, gave an important speech warning of increased Russian activities in UK waters. The threats posed by Moscow, he said, are greater today than at any point since 1989 and ‘felt most acutely in the maritime domain, in the North Atlantic, in the High North’.

Just as Iran has understood that the Strait of Hormuz gives leverage, so too does Moscow recognise the influence it could wield as shipping lanes open up along its 15,000-mile Arctic coastline and become more important for global trade. Prowling the waters at either end of the Northern Sea Route are 12 of Russia’s nuclear-armed submarines – six stationed on the Kola Peninsula in the west and six operated by the Pacific Fleet based in Vilyuchinsk on the Kamchatka Peninsula.

In between, Russia has spent years reopening, modernising and fortifying military bases on its Siberian coast, making the route a formidable gauntlet for any rival power.

Most of the American forces in the region – some 22,000 military personnel – are concentrated on Alaska’s northern shore, across eight bases. Greenland, however, could become Washington’s hub of operations in the North Atlantic, if US forces move in following Trump’s agreement with the Danish.

America already operates the Pituffik Space Base on Greenland, and will want to resurrect several of its long-abandoned Second World War bases there to enhance missile warning, space surveillance and satellite capabilities. It was one of these derelict sites – at Gronnedal – that a Chinese firm wanted to buy in 2016, until Denmark blocked the deal on security grounds.

Elsewhere, Nato has a military presence on Canada’s Arctic islands and along Norway’s northern coast. The Norwegians have by far the strongest military presence in the Arctic among its Scandinavian neighbours, with four air bases, including one for its new F-35 fighter jets; two navy bases and a string of army bases.

It also runs the Trondelag Reception Centre, a military hub that can swiftly house Nato troops during an attack. Nearby is Camp Viking, Britain’s main toehold in the region – a hub for the UK’s Commando Force led by the Royal Marines, which is aiming to have a year-round presence there.

All of which is to say that the Arctic could become every bit as much of a tinderbox as the Middle East, were the Northern Passage to open to significant global trade.

Perhaps for that reason, Russia has been wary of over-involving China in its Arctic policy. Although there have been joint training exercises, Moscow has sought to keep its primary geopolitical partner at arm’s length when it comes to the High North.

That is now changing as Russia’s isolation from the West deepens: around half the transits last year either began or ended in China, while Chinese money supports Russian energy projects. Joint exercises also provide an indication of close collaboration across this region.

The Arctic as a whole is not just a new frontier for the study of climate change, for the extraction of minerals or for land grabs; it is a key part of the reality that control of trade routes has always been fundamental to power.

Here in the United Kingdom, as in Europe, there are lots of things we need to be doing to set our house in order.

One of the most important, though, is to understand what is changing, where and why. And another is to not only to look to the East and to the West, or even to the South – as we often do. We need to remember to look to the North too.

Peter Frankopan is Professor of Global History at Oxford University.