What if the UK has to defend the North Atlantic alone?
Gold award winner for the First Sea Lord’s Essay Competition 2025
This piece was written in April 2025 for the First Sea Lord’s Essay Competition, and was awarded Gold at the International Sea Power Conference 2025.
The United Kingdom (UK) is positioned at the heart of the North Atlantic, which ‘encompasses the area between Newfoundland-Iberia and the Eurasian Basin in the Arctic Ocean’. This peculiar geography has meant security, prosperity and sea power throughout British history. Yet, it also entails responsibilities, such as defending the area with the Royal Navy – an activity which the UK may be soon forced to carry out alone.
Although the threats made by Donald Trump, President of the United States (US), of leaving the North Atlantic Treaty Organisation (NATO) may be just a strategic move to push members to increase military expenditure, uncertainty looms over the future of the transatlantic alliance. If American security guarantees really disappeared, Britain would find itself facing new scenarios.
New priorities, AUKUS review and new partnerships
Considering, as noted by the Council on Geostrategy, that ‘the UK relies on the sea for security, energy, trade and prosperity’ it cannot be disregarded that if security increases in importance, the other three dimensions may lose their centrality and see their weight diminished. Arguably, the recommended deployment of naval units in the Indo-Pacific, also aimed at strengthening British influence and trade in the area, would become infeasible with current Royal Navy equipment.
Having to defend the North Atlantic alone, the UK should rethink its ambitions to play a more prominent role in the Indo-Pacific, repositioning its fleet closer to home, and abandoning actions aimed at contrasting such illegitimate claims as those made by the People’s Republic of China (PRC) in the Taiwan Strait. In fact, since France is also directly contributing to maritime security in the South China Sea, Britain could try to propose an exchange where it relocates some of its vessels to the North Atlantic – where they would also enhance the security of French waters – to be replaced by a more substantial French presence in the Indo-Pacific. If such an option gained substance, ‘Global Britain’ would likely return to just ‘Britain’, with a more Eurocentric or Atlanticist perspective.
However, in September 2021, AUKUS established the rejection of a distinction between the Euro-Atlantic and Indo-Pacific theatres; a fact which suggests that the UK would not be entirely alone, and may receive significant support – at least from Australia. In other words, if AUKUS becomes a two-power pact, the remaining countries may split their responsibility, becoming ‘UKA’ in the North Atlantic and ‘AUK’ in the Indo-Pacific. While it is plausible that the US may overturn its strategy and alliances in the North Atlantic, it remains much more questionable that it alters its plans in the Indo-Pacific. Pacts such as AUKUS do not involve the European Union (EU), to which Trump seems to address most of his resentment. In particular, the AUKUS programme will likely be late and over budget, including the joint construction of nuclear submarines which will not be ready until 2040. This suggests that such cooperation will last for a while.
His Majesty’s (HM) Government’s 2021 Integrated Review will consequently need significant updates. The document provides insights about the future development of nuclear deterrence in Britain, mentioning enhanced cooperation between the UK, the US and France. Britain’s commitment to the nuclear Non-Proliferation Treaty (NPT) is reaffirmed, although the dramatic change in the international relationships with America may put this aspect under scrutiny in the future. As such, the UK should be prepared for any scenario.
Pacts such as AUKUS emphasise how Britain may reinforce its position. The UK could try to build new coalitions attempting to involve India in the Indo-Pacific, as well as with new partners in the North Atlantic. Specifically, it could volunteer to replace the US in contributing to Iceland’s defence. Not only does Iceland adhere to the Memorandum on Nordic Defence Cooperation (NORDEFCO), but it has also concluded bilateral agreements with Atlantic countries such as Canada, Denmark and Britain. For this reason, since a form of cooperation already exists, it should not be too hard for London to strengthen its relationship with Reykjavík, and replace the US as Iceland’s main partner.
This alliance building would likely require massive investments in military spending, but it could also result in an expansion of the UK’s command nodes. Such a strategy points towards a possible enlargement of Britain’s presence in non-traditional chokepoints, such as the Faroe Islands, St. Pierre and Miquelon, the Azores and southern Greenland. Yet, despite the advantage of guarding the North Atlantic from all its corners, this layout would require significant diplomatic and economic efforts. Moreover, in these operations, the UK may be stifled by the disagreement of the regions involved – presumably by the US, unhappy with leaving the control of the North Atlantic de facto to the UK.
In this framework, Greenland’s future will be pivotal. The largest Arctic island hosts an EU office in its capital and relies on Denmark for security, despite its growing hunger for independence. Britain could profit from this, with a shared insular nature and a similar view of continental Europe (Nuuk left the EU in 1985). A contribution to Greenland’s security through the Royal Navy could provide the UK with an additional ‘seapower stronghold’ at the opposite side of the North Atlantic, and therefore a more solid control of the region.
When it comes to partnerships, however, there is an even more optimistic scenario. Exercise TAMBER SHIELD, conducted in conjunction with the Royal Norwegian Navy, has been run three times, fostering a higher level of integration and cooperation between the two fleets. There may be room for negotiations aimed at a partition of North Atlantic security operations, where Norway leads the military management of the ocean’s upper portion located north of Iceland, and Britain would take care of the waters south of Iceland.
This hypothesis is also plausible because both Norway and the UK are NATO members but not EU members, and therefore have greater autonomy in the decisions they would need to make for this plan to gain substance. Furthermore, Norway would be facilitated in this task by its proximity to Svalbard: although demilitarised, the archipelago belongs to Norway, which could involve Britain thanks to the possibility offered by the Svalbard Treaty. Finally, the UK may consider expanding Project KRAKEN to an international dimension, involving North Atlantic nations.
Tough choices for the military
Along with the above, Britain should also necessarily manage an enlargement of the Royal Navy, updating its capacity of deterrence and maritime influence. HM Government may employ savings from the latest welfare cuts, not just to add laser-equipped warships, but also to develop new units which combine naval warfare with aerial. The fact that the DragonFire laser technology employed will have a very limited cost will leave a higher margin for other projects, such as the combination of ships and drones which presents remarkable opportunities for efficiency and improvements.
In other words, drones carriers may be less expensive and more lethal than aircraft carriers, with the possibility of employing nuclear drones. These are automated uncrewed instruments, whereas real people may be sent as spies on the field to acquire information and influence military maritime politics from within, as ‘CRINK’ nations – the PRC, Russia, Iran and North Korea – have traditionally done, compared to technology-leaning free and open nations.
In order not to leave the Indo-Pacific, the Royal Navy may take inspiration from the US’ ‘Two-Ocean Navy’, and it should take into account possible issues with communication and satellites. If Elon Musk’s Starlink cannot be trusted, the UK would have to find another partner such as Eutelsat, although it remains questionable whether Eutelsat possesses the necessary resources to develop a satisfactory network of satellites, and this even in a short period of time.
It is also appropriate to remark that such an attempt would require careful consideration in order to avoid the uncertainty encountered, or mistakes which have been made when Britain has tried to model its decisions or strategies according to the American standards. An example can be identified in the Advanced Research and Invention Agency (ARIA), conspicuously funded to become an independent body contributing to the UK’s security, but essentially being very similar to the American Defence Advanced Research Projects Agency (DARPA).
To summarise, the possibility that Britain is left alone in defending the North Atlantic is seen as remote, although the Royal Navy should be prepared. It can do so by reorienting its priorities and resources towards the North Atlantic, and by forging new strategic partnerships with key players in the area.
Dr Emanuele Maggioli is a Doctor of Philosophy in Global Studies (Politics and International Relations) and an independent early-career researcher.
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As someone who lives in Japan I find the British idea that they are somehow still a significant player in the Pacific rather hilarious.
Brilliant strategic thinking on the Iceland partnership angle. The geographic leverage fromcontrolling both ends of the GIUK gap through UK-Norway-Iceland cooperation is understated in most defense discussions. I worked adjacent to NATO exercises back in the day and the communications piece with Starlink reliability is a real vulnerability noone seems to address openly. Reorienting AUKUS into regional theaters makes way more practical sense than trying to be everywehre at once.