DHN0037

Written Evidence submitted by the Air & Space Power Association, Freeman Air & Space Institute, King's College London.

Summary

The High North must principally be treated as an integrated air, space and maritime domain, requiring close coordination with Allies. The UK should strengthen its leadership within NATO and regional groupings, while enhancing national capabilities, by expanding airborne ASW/ASuW capacity, developing theatre-level ISR (including a HADES-like capability), increasing the E-7 fleet, bolstering the RAF fleet’s endurance and range with sovereign boom refuelling capacity, and improving space contributions through initiatives such as STARLIFT and NORTHLINK.[1] It should also exploit the maritime potential of uncrewed and high-altitude systems alongside crewed platforms. Finally, it should clarify the role and capacity of its combat air force to ensure credible, sustained operations in the region.

Note: This submission focuses on two areas of the Committee’s call for evidence, from an air and space power perspective: i) how will the UK work with allies? and ii) is the UK capable of sustained operations in the High North?

The Authors

Through events and independent analysis, the Freeman Air & Space Institute and the Air & Space Power Association are committed to the advancement and understanding of air and space power in the UK and beyond.[2]

How will the UK work with, and without, key allies and partners in the region, both within and outside NATO, including through the JEF, and how does this support or undermine the UK’s policies?

1.              While many regions matter to the UK, the High North is unique in concentrating commerce, climate and conflict risks so close to home.[3] The MOD’s approach to the region, referred to in this submission as the Defence Arctic Strategy (DAS), prioritises: protecting critical national infrastructure; ensuring freedom of navigation; reinforcing the rules-based international system; and countering destabilising behaviour.[4] These objectives remain valid given the enduring challenges posed by Russia and China.

2.              However, the DAS is stronger on description than delivery. As well as lacking clarity on timelines and accountability, it treats maritime activity as routine while air and space contributions are framed as periodic,” “on an opportune basis” or longer-term.[5] This creates a mismatch between stated ambitions and the multi-domain effects required to operate credibly in the High North.

3.              Allied capabilities can compensate to a degree, and the UK has, since the 1960s, assumed that its major operations would be NATO or coalition efforts, not unilateral undertakings.[6] But the UK’s principal ally is retrenching from Europe and, at times, acting in destabilising ways, generating uncertainty about the scale and shape of US military support.

4.              Therefore, to achieve the DAS’s objectives, the UK will need to work with Allies and partners while reducing collective reliance on US enablers. Doing so requires a rational alignment of interests (not sentiment alone), solid institutions and equitable burden-sharing – three attributes of enduring alliances.[7] The remainder of this section assesses how far UK air and space operations meet these conditions at the NATO, mini- and bilateral levels,[8] and how national dynamics may shape this in future.

NATO

5.              NATO will remain the primary framework for High North cooperation, consistent with the Government’s “NATO-first” approach.[9] However, the Alliance lacks an agreed strategy towards the region, bar calling Russian capabilities in the High North a “strategic challenge.”[10] This limits NATO’s ability to act proactively, particularly below the threshold of armed conflict.[11]

6.              The forthcoming Summit in Ankara gives the UK and like-minded Allies an opportunity to align interests, articulate the threats emanating from the High North, and press for greater NATO activity therein. This will provide greater political clarity ahead of the 2027 NATO Defence Planning Process cycle, which will set capability targets across the Alliance for the years ahead. 2027 also coincides with the deadline the US has set for Europe to assume responsibility for the bulk of the Alliance’s conventional defence.[12] That makes the next 12 months a critical period in determining the UK’s regional role.

7.              And expectations will be high. Institutionally, a British senior officer is now expected to command Joint Force Command Norfolk (JFC-NF) and, by extension, NATO’s Regional Plan North West, which includes the High North. The UK will thus occupy a prominent role on the Alliance’s northern flank despite not being an Arctic state. To that end, this year’s carrier strike deployment represents a welcome step towards burnishing the UK’s air power credentials. But without sufficient capabilities or presence, Britain risks holding formal leadership positions while possessing limited operational influence.  Such an erosion of our credibility with allies would affect our ability to deter.

8.              It is true that the UK already participates in several NATO initiatives potentially relevant to the High North. These include the Cross-Border Airspace Initiative to enhance training and readiness, and initiatives developing remotely piloted air systems, passive air surveillance sensors, advanced munitions, and responsive space launch under the STARLIFT programme.

9.              However, the UK has several air and space capability deficiencies which undermine its ability to enable or lead NATO and Joint Expeditionary Force (JEF) operations in the High North. These are covered in detail in the second part of this submission. At this stage, it will just be said that the UK should support Norway’s newly established Combined Air Operations Centre to further integrate Allied air operations in the High North, just as it does with NATO’s other two facilities in Spain and Germany.[13]

Multi- and Bilateral Relationships

10.              Alongside NATO, smaller groupings provide flexibility and speed. The JEF is a coalition of ten like-minded nations, focused on North Atlantic, Baltic and High North security with the UK leading as its “framework nation,” making it well suited to addressing grey-zone activity in the region.[14] Although shared interests were never in any doubt, institutionally and capability-wise, the JEF has recently lost momentum.[15]

11.              The UK’s command of JFC-NF could provide renewed strategic focus. It should use its leadership positions to rehearse the transition from JEF-led operations to NATO ones in preparation for a crisis. Additionally, despite the UK now spending proportionally less on defence than most of the JEF nations it is meant to lead,[16] there are some promising areas of capability collaboration, such as with Norway, as discussed below.

12.              As for the EU, last year’s UK-EU Defence Partnership refers to the Arctic as one of seven priority regions for cooperation so, in reality, it is unlikely to receive focused attention.[17] Given also the ongoing challenges with UK accession to SAFE (Security Action for Europe), collaboration with the EU is not expected to meaningfully advance UK air and space power in the High North specifically.

13.              Bilaterally, recent US policy frames the Arctic in terms of hemispheric defence, carving out areas of interest while neglecting others.[18] Retaining credibility with the US military – including US Northern Command and Arctic-experienced National Guard units[19]will preserve an important buffer against political volatility in Anglo-American relations. As well as common aircraft (e.g. P-8, F-35, E-7, RC-135 and C-17[20]), UK facilities such as RAF Fylingdales and RAF Menwith Hill are central to this dynamic, supporting missile warning and space surveillance missions that are becoming increasingly important to Washington, as reflected in its recent interests in Greenland and Golden Dome.

14.              Within Europe, Norway remains the UK’s most significant partner in the High North, with shared interests, deepening institutional links, and growing industrial collaboration. Both countries operate the P-8A Poseidon and F-35 Lightning, and British helicopter units regularly train in northern Norway.[21] These shared capabilities underpin the 2024 Lunna House Agreement,[22] which offers a foundation for deeper integration particularly in uncrewed systems and personnel exchanges. In future, however, the Nordic air forces (Denmark, Finland, Norway and Sweden) expect to operate as one through the Nordic Air Power Concept.[23] Engaging with this construct may offer additional opportunities to strengthen air and space collaboration in the High North.

15.              Until then, the bilateral Lunna House Agreement provides a good model for a country like Canada given that it will also be operating the P-8A and F-35, and has a growing interest in Arctic security. This could provide Canada with a halfway house for JEF membership without, as some fear, distorting the JEF’s remit. Likewise, under the Trinity House Agreement,[24] another non-JEF nation, Germany, will periodically deploy P-8s to RAF Lossiemouth, augmenting the UK’s maritime patrol coverage of the High North. Cooperation with other partners – Iceland (via NATO air policing) and Ireland (on critical national infrastructure protection) – may similarly need to deepen despite historic sensitivities.

16.              Sustaining these relationships requires regular training across the High North, where conditions vary significantly between the European and North American sub-regions. To date, this has not been happening, leading the Chief of the Air Staff to publicly question whether the RAF can mount prolonged operations in the High North.[25]

National Considerations

17.              Ultimately, international relationships are necessary but insufficient. Good strategy depends on “an explicit awareness of clear national priorities and…the realistic trade-offs to be made in adopting and maintaining strategic coherence.”[26] The UK has not always recognised this. Commitments elsewhere – such as a putative reassurance force in Ukraine or operations in the Middle East – risk diluting focus on the northern flank. If that happens, it could bring into question the viability of the Royal Navy’s embryonic concepts: Atlantic Bastion, Atlantic Shield and Atlantic Strike, for while these are maritime-led, they cannot operate successfully without air and space power.[27] And yet, air power is “typically the UK government’s first tool of choice when the use of armed force is required overseas,[28] a reality recent air deployments to the Middle East have shown.

18.              UK success in the High North will therefore depend on three interlocking factors: credible leadership within NATO (notably from JFC-NF); deepened mini- and bilateral cooperation, especially with JEF partners and Norway; and national coherence between capabilities and commitments.

Recommendation 1: The Government should press NATO to define a clear Arctic role, use its leadership of JFC-NF to revitalise the JEF and rehearse transitions to NATO operations, deepen cooperation with key allies – including by exploring a Lunna House-style agreement with Canada – and underpin these efforts with realistic training and a coherent defence policy.

Do the UK Armed Forces have appropriate capabilities for sustained operations in the region now; and are appropriate plans in place to meet the needs of the future?

19.              The High North poses acute challenges due to its polar geography, harsh climate, vast sea and ice, and limited land bases. These conditions increase reliance on scarce enablers for persistent surveillance and communications, while demanding platforms with greater endurance, range and persistence than elsewhere. It is principally an integrated air, space and maritime domain, with littoral land forces dependent on air support for logistics, protection and strike capability. Effective operations require coordinated, multi-domain activity across a wide area. NATO is pursuing this under an operational approach known as Arctic Sentry, which JFC-NF will lead.

20.              Arctic Sentry prioritises the following:

21.              Given NATO’s priorities and the UK’s ‘NATO First’ approach, it is logical to assess each area from a UK air and space perspective.

ISR

22.              The 2021 retirement of the Sentinel R1 removed wide-area ground surveillance, a capability that was optimised for the European theatre. More recently, the cancellation of the Shadow R2 tactical ISR programme has further stunted the RAF’s ability to conduct ISR.[30] In a High North context, where Russia’s Northern Fleet and long-range aviation remain central to Moscow’s strategy, the gaps are especially concerning. A modern airborne ISR platform similar to the United States Army’s HADES would help address these worrying capability shortfalls.[31] Operating at high altitude and long stand-off ranges, a HADES-like capability would combine advanced radar intelligence, signals intelligence and wide-area surveillance, while also deploying air-launched sensing payloads for extended reach. Such a platform would complement, not replace, the RAF’s RC-135W Rivet Joint by providing theatre-level sensing, cueing and targeting. It could also take on many of Shadow’s roles and restore and exceed Sentinel’s lost capabilities.

23.              At sea, the UK now fields a potent ASW and ASuW capability in the P-8A Poseidon, complementing the Royal Navy’s shorter-range fleet defence of Merlin and Wildcat helicopters. However, with only nine aircraft procured, below the widely cited minimum of 13[32] (Australia has ordered 14[33]), North Atlantic coverage and persistence will be constrained, particularly given maintenance demands. This can be offset somewhat by multi-national co-ordination to share the load, but the use of uncrewed systems and, as discussed below, additional air-to-air refuelling capability compatible with the P-8A boom system should be prioritised.

24.              These shortfalls are compounded by the UK’s long and risky ‘capability holiday’ in Airborne Early Warning and Control (AEW&C), between the retirement of the E-3D Sentry fleet in 2021 and the much-delayed introduction of its successor E-7 Wedgetail aircraft later this year.[34] Interim measures are inadequate. Crowsnest, a Royal Navy system slated for retirement in 2029,[35] is optimised for fleet defence and is very limited in its ability to detect long-range drones, bombers, stealthy cruise missiles and hypersonic weapons given its short-range, low-altitude and low-endurance. Until the UK’s E-7s come online, the UK is wholly reliant on NATO’s ageing E-3A Sentry (in many ways a less capable system than the RAF’s now-retired E-3D). These E-3As are, in any case, ageing and unreliable, and are largely devoted to missions policing NATO’s Eastern flank. And even once the RAF E-7s are delivered, only three are planned (replacing seven E-3Ds), meaning UK resilience and persistence will be too limited to sustain even a single 24/7 orbit for a meaningful duration. Expanding the fleet, as suggested in the 2025 SDR, to five aircraft, is critical to rebuilding the UK’s integrated air and missile defence.[36]

25.              The endurance, range and consequent effectiveness of both the P-8 and E-7 would be improved through air-to-air refuelling, but the RAF currently depends on Allies, especially the United States Air Force, as its own Voyager tankers lack the boom equipment necessary to refuel these types (as well as the RC-135W, C-17A and the on-order nuclear-capable F-35A). This means that, its ISR and embryonic nuclear strike architecture cannot fulfil their necessary potential. Insufficient fleet sizes, loss of key surveillance platforms, an ongoing AEW&C shortfall, and the absence of a sovereign air-to-air refuelling capability need addressing urgently. Nowhere would these limitations be more keenly felt than in the High North, from where the principal airborne and submarine threats from Russia to NATO are most likely to emerge.

Recommendation 2: The Government should consider options to increase sovereign ASW/ASuW airborne capacity (crewed and uncrewed).

Recommendation 3: The Government should consider acquiring a long-range, long-endurance multi-sensor ISR capability such as the US Army’s HADES.

Recommendation 4: The Government should expand the E-7 order to a minimum of five aircraft.

Space

26.              The polar region is poorly served by communications and navigation satellites, which are typically equatorial. This creates a mismatch between high reliance on space-based connectivity and limited coverage, partly due to low commercial demand at the poles.[37] While polar and sun-synchronous satellites support ISR, their numbers are limited, leading to lower revisit rates and higher latency, and few are UK-owned.

27.              The UK’s emerging space launch capabilities present a significant opportunity for allies to bolster space control and coverage of the High North. Its geography is well suited for launching into polar and sun-synchronous orbits for sovereign and NATO missions. Combined with mature satellite manufacturing capability, the UK is ideally placed to lead this activity, especially in the European context, as other nations do not have the luxury of large sea expanses to their north for launch overflight. NATO’s STARLIFT Initiative highlights the need for rapid launch capability; while challenging, the UK’s licensed launch sites, industrial base, and supply chain expertise make this a realistic leadership role.

28.              The UK is also absent from NORTHLINK, NATO’s Arctic satellite communications programme. With Skynet offering limited coverage above 70° North,[38] participation would enhance situational awareness and reinforce UK credibility, especially as more distant allies such as Germany, Hungary and Italy are already involved.

Recommendation 5: The Government should consider a leading role in the STARLIFT initiative and consider joining NORTHLINK.

Uncrewed Air Systems

29.              The UK’s current drone programme, while advanced, provides no meaningful maritime surveillance capability. However, the MQ-9B Protector could fulfil this role if fitted with maritime radar and sonobuoy dispensers, complementing the P-8A Poseidon’s ASW capabilities, particularly as anti-aircraft threats are less pronounced at sea than overland. High-altitude, long-endurance air vehicles acting as pseudo-satellites could also deliver persistent surveillance and communications in the High North, where space-based systems are limited. These are more vulnerable to interception and harsh weather but remain cost-effective in pre-conflict intelligence and deterrence roles.

Recommendation 6: The Government should develop the maritime potential of the MQ-9B and high-altitude systems, but as complementary to, not replacements for, high-end crewed platforms.

Extreme Cold

30.              Many major UK air platforms are designed and certified for cold environments, including the High North. However, while aircraft are capable, personnel and supporting equipment are less prepared. This includes basic needs such as appropriate clothing, as well as training to operate effectively in extreme cold and icy conditions.[39] Ancillary equipment used to support aircraft must also function reliably in these environments. Deployments to diverse High North regions such as Scandinavia, Alaska and Canada provide valuable opportunities to build experience, test both personnel readiness and equipment suitability, and reinforce regional ties.[40]

Recommendation 7: The Government should ensure regular training in the High North to ensure that UK personnel are able to maintain mission rates and readiness.

Control of the Air

31.              Finally, while not a stated focus for Arctic Sentry, control of the air is a fundamental prerequisite for operations in the region. Alongside the RAF’s anti-submarine role, the air domain remains highly contested, with regular probing flights near Norway and the UK likely to continue. Intercept missions are conducted with Scandinavian allies and NATO policing from Iceland, requiring multiple operating locations and significant air-to-air refuelling.

32.              Although this capability is well established, the scale of the area remains a challenge. Sufficient air defence assets, Airborne Early Warning, and refuelling support are essential to maintain air control and enable ASW and ASuW operations. Carrier-based assets can contribute but require land-based support to sustain combat air patrols. Notably, the US provides 65% of NATO’s fast jets, 65% of the capabilities required for the suppression of enemy air defences, and 90% of air refuellers.[41]

Recommendation 8: The Government should establish what the role and attendant spare capacity is of the RAF’s Combat Air Force for High North operations.

Summary

33.              The High North is as much an air and space domain as it is a maritime one, and these three elements need to be closely integrated along with regional Allies. To ensure it achieves that, the following recommendations are made:

Recommendation 1: The Government should press NATO to define a clear Arctic role, use its leadership of JFC-NF to revitalise the JEF and rehearse transitions to NATO operations, deepen cooperation with key allies – including by exploring a Lunna House-style agreement with Canada – and underpin these efforts with realistic training and a coherent defence policy.

Recommendation 2: The Government should consider options to increase sovereign ASW/ASuW airborne capacity (crewed and uncrewed).

Recommendation 3: The Government should consider acquiring a long-range, long-endurance multi-sensor ISR capability such as the US Army’s HADES.

Recommendation 4: The Government should expand the E-7 order to a minimum of five aircraft.

Recommendation 5: The Government should consider a leading role in the STARLIFT initiative and consider joining NORTHLINK.

Recommendation 6: The Government should develop the maritime potential of the MQ-9B and high-altitude systems, but as complementary to, not replacements for, high-end crewed platforms.

Recommendation 7: The Government should ensure regular training in the High North to ensure that UK personnel are able to maintain mission rates and readiness.

Recommendation 8: The Government should establish what the role and attendant spare capacity is of the RAF’s Combat Air Force for High North operations.

 

25th March 2026


[1] ASW: Anti-Submarine Warfare; ASuW: Anti-Surface Warfare; ISR: Intelligence, Surveillance and Reconnaissance; HADES: MC-55A High Accuracy Detection and Exploitation System.

[2] This submission builds on the authors’ prior work, including Arun Dawson, “Cold Comfort: The Challenges Facing the RAF’s Return to the High North,” Freeman Paper 12, 2022.

[3] The Arctic, High North and Wider North are terms subject to some contention. The former generally refers to the region enclosed by the Arctic Circle; the latter two are not geographic but rather fluid, political constructs. High North is usually taken to mean Northern Europe and the North Atlantic. The Wider North is much more expansive, describing a region from the North American continent to the Baltics. This is to say nothing of the Arctic immediately adjacent to the Pacific – variably referred to as the Eastern Arctic and Pacific Arctic – which has received less attention by academics and policymakers. Alec Smith et. al., “Why does the Arctic matter to Britain?” Council on Geostrategy: Big Ask, 10 October 2025.

[4] Ministry of Defence, UK Defence Contribution to the High North, 2022, p.8.

[5] Although, with respect to the Royal Navy, the DAS speaks of “routine naval operations in the High North” in one sentence and “a periodic Royal Navy presence in the High North” in the next, which is at best unclear. Ministry of Defence, UK Defence Contribution to the High North, 2022, p.11-13.

[6] William James, “Who are Britain’s most important allies and partners?Council on Geostrategy: Primer, 2024, p.1.

[7] Strong institutions include “regular ministerial dialogues, personnel exchanges, military exercises and defence-industrial cooperation.” William James, “Who are Britain’s most important allies and partners?Council on Geostrategy: Primer, 2024, p.11-14. See also Michael Clarke, The Challenge of Defending Britain (Manchester: Manchester University Press, 2019), p.90.

[8] Mini-laterals are small grouping of like-minded nations focused on a particular policy area. An example is the Joint Expeditionary Force. Nele Loorents, “The role of minilateral cooperation in enhancing Baltic and European security,” Council on Geostrategy: The Memorandum, 23 February 2026.

[9] The accession of Sweden and Finland to the alliance underlines NATO’s importance in the High North. UK Government, Strategic Defence Review, 2025, p.4.

[10] NATO, Strategic Concept, 2022, p.4, para.8.

[11] Consequently, some have suggested that activities like Arctic Sentry are reactive and small scale, ceding the initiative to adversaries. Senior NATO official.

[12] Gram Slattery and Humeyra Pamuk, “Exclusive: US sets 2027 deadline for Europe-led NATO defense, officials say,” Reuters, 6 December 2025.

[13] NATO, “NATO opens new Combined Air Operations Centre in Norway,” nato.int, 10 October 2025.

[14] Rosie Knighton, “What is the Joint Expeditionary Force?” House of Commons Library Research Briefing, 6 August 2024, pp.2-3.

[15] Ed Arnold, “Joint Expeditionary Force is a British defence success, but UK credibility is under threat,” Forces News, 12 December 2024.

[16] Tim Wallace, “Britain tumbles down Nato rankings despite Starmer’s spending pledge,” The Telegraph, 3 January 2026.

[17] European Union and the United Kingdom, Security and Defence Partnership, 2025, p.4, para.14.

[18] The transfer of Greenland from US European Command to US Northern Command reflects a growing tendency in Washington to treat parts of the Arctic as an extension of homeland defence rather than the European theatre. Also see Ministry of Defence, Future Operating Environments 2040, 2026, pp.13-14.

[19] Norway’s collaboration with the Minnesota National Guard provides a model. US Department of Defense, Defense Arctic Strategy, 2024, p.13.

[20] The overwhelming majority of which are capable of in-flight refuelling from ‘boom’ equipped tankers, of which the RAF has none.

[21] Alongside the Royal Navy, Norway will also operate the Type 26 anti-submarine warfare frigate.

[22] UK Government, “UK and Norway to operate together to counter Russian undersea threat through major new defence agreement,” gov.uk, 4 December 2025.

[23] Norwegian Ministry of Defence, “Four Nordic Air Forces Fighting as One,” forsvaret.no, 3 March 2025.

[24] UK Government, “Landmark UK-Germany defence agreement to strengthen our security and prosperity,” gov.uk, 22 October 2024.

[25] Tom Cotterill, “Britain’s jets could struggle in Arctic cold, RAF chief says,” The Telegraph, 17 February 2026.

[26] Michael Clarke, The Challenge of Defending Britain (Manchester: Manchester University Press, 2019), p.75.

[27]The Royal Navy cannot build a bastion alone. Royal Air Force (RAF) capabilities, including airborne surveillance, fighter cover, tankers and Maritime Patrol Aircraft (MPA), will play a significant role.” William Freer and Matthew Palmer, “Exit ‘Fourth battle of the Atlantic’; enter ‘Battle of the Bastions’: Part 2,” Council on Geostrategy: The Memorandum, 17 December 2025.

[28] Justin Bronk, “Combat Air Choices for the UK Government,” RUSI Occasional Paper, 2020, p.2.

[29] NATO, “Arctic Security,” nato.int, 16 February 2026.

[30] George Allison, “UK scraps Shadow MK2 upgrade due to cost, capability issues,” UK Defence Journal, 7 November 2025.

[31] A reduction in the US order may provide an opportunity to acquire HADES in a timely manner. Jen Judson, “US Army halves spy plane fleet before first takeoff,” Defense News, 16 May 2025.

[32] AVM Andrew Roberts, a specialist in maritime patrol, recommends 15. Andrew Roberts, “Written Evidence: AFR0007,” parliament.uk, 2023.

[33] Australian Government, “Second P-8A Poseidon Squadron established to support growing aircraft fleet,” defence.gov.au, 17 October 2025.

[34] The holiday has been so long, parts of the E-7 have become outdated. Richard Thomas, “UK E-7 Wedgetail facing ‘obsolescence’ issues before even entering service,” Airforce Technology, 20 March 2026.

[35] George Allison, “New Govt keeps plan to scrap Crowsnest after four years,” UK Defence Journal, 28 January 2025.

[36] UK Government, Strategic Defence Review, 2025, p.115.

[37] US Department of Defense, Defense Arctic Strategy, 2024, p.9.

[38] The DAS committed to continued investments in mobile troposcatter technology to “enable high bandwidth, secure long-range communication” in places like the High North – and these systems have reportedly been delivered to the Royal Marines and British Army – but it is unclear whether these systems can match the wide-area, multi-user coverage NORTHLINK is intended to provide. Ministry of Defence, UK Defence Contribution to the High North, 2022, p.13.

[39] On the importance of training, see Phillips Payson O’Brien, War and Power: Who Wins Wars – and Why (London: Penguin Random House, 2025), p.169.

[40] US Department of Defense, Defense Arctic Strategy, 2024, p.6.

[41] Gen. Sir James Everard, “Oral Evidence on the US, UK and NATO: HC 184,” House of Commons Defence Select Committee, 24 May 2022, Q.144.