Japan’s Evolving Security Strategy

Introduction

One of Prime Minister Sanae Takaichi’s most consistent pledges during and after her ascent to office has been the revision of three key security policy documents, namely, the ‘National Security Strategy’, the ‘National Defence Strategy’ and the ‘Defence Buildup Programme’. Upon entering office in October 2025, she tasked Defence Minister Shinjiro Koizumi with promulgating newer versions of all three documents, which were first adopted in 2012 and subsequently revised in 2014 and 2022.^[1] To facilitate this process, a high-level committee (防衛力変革推進本部, Headquarters for the Promotion of Changes in Defence Capability) was convened within the Ministry of Defence.

On 12 March 2026, the committee released a preliminary document entitled ‘防衛力の変革の方向性①’ (‘Directions of Change in Defence Capabilities 1’), which offers a valuable glimpse into the evolution of Japan’s security strategy in a period of unprecedented volatility.^[2] Though presented as an outline (possibly the first in a series), the document offers insights into the direction of travel that may, in days to come, culminate in new security doctrines.

Stand-off Defence Capabilities

According to the document, stand-off capabilities enable the defence of Japan’s outlying islands against external invasion at a stand-off distance while minimising risk to SDF members. Through a mix of missile types, Japanese defence planners aim to enable overlapping responses while forcing adversaries to deal with multiple systems at once, which they argue would blunt any direct assault on Japanese forces. Coupling this with the optimum use of unmanned assets would enable maximum survivability for SDF forces. This latter point is explicitly identified as a critical consideration for an armed force that serves and defends a country undergoing a steep and (hitherto) irreversible population decline.^[3]

The above lessons are drawn from the conflict in Ukraine, which serves as the overarching model for the document’s planners.^[4] Thus, the key considerations around which Japan’s strategic evolution is foreseen are: strengthening the targeting capabilities of weapons platforms to enable the ‘practical use’ of stand-off missile capabilities; devising effective strategies that enable the potent combination of missiles and unmanned assets on the battlefield; and securing the necessary capabilities that can withstand a prolonged (or stalemated) conflict.^[5]

Integrated Air and Missile Defence (IAMD)

Integrated air and missile defences are more explicitly identified as a response to the developing capabilities of Japan’s regional adversaries, namely, the Democratic People’s Republic of Korea (DPRK), China and Russia. The document cites real examples of such capabilities, such as the 52 times DPRK missiles have been launched since 2023, the 3,000-strong surface-launched missile capability developed by China and the use of advanced ballistic, cruise and hypersonic cruise missiles by Russia during the Ukraine conflict.^[6] The document highlights the use of multi-layered air defence capabilities to blunt and mislead incoming attacks as an important component of Ukraine’s response to Russia’s conflict, while also underlining Russia’s use of combined drone and missile attacks to impose high costs on Ukrainian air defences. At the same time, strikes on public infrastructure, such as power generation facilities, undermine Kyiv’s capabilities and force it to fight a long war of attrition.^[7]

Based on these considerations, the document weighs the necessity of developing means to positively shoot down not only missiles but also more advanced platforms such as drones and hypersonic glide vehicles. It also emphasises coming up with what it calls a ‘best mix’ (ベストミックス) of countermeasures capable of not only intercepting, but also dispersing and confusing incoming threats, which can be operated in a network. Finally, it speaks of the need to procure all the above kinds of assets in sufficient quantities to withstand a protracted conflict.^[8]

Sea-lane Security

Sea-lane security, particularly in the Pacific Ocean region, is the third major direction outlined in the document. Clearly identifying the vital dependencies created by its island location on resources transported across sea lines of communication (SLOCs), the document argues that for Japan, the vast web of SLOCs spread out across the Pacific, Indian and Atlantic Oceans can usefully be collapsed into a focus on the Pacific ‘theatre’ alone. These vital sea lanes, which carry 99.5 per cent of Japan’s trade volume, nearly 100 per cent of its total energy supply and around 62 per cent of its food imports, are recognised as particularly vulnerable to disruption and stoppage by the actions of various parties.^[9] As examples, it points to the increasing activities of the navies of China and Russia, the former of which is identified as particularly effective in operating in ‘far seas’ due to its indigenously-built aircraft carriers. Interceptions from the air, by Chinese and Russian bombers operating in tandem, are also identified as a threat.^[10]

The document identifies glaring gaps in its Pacific domain awareness, stating that its ‘information-gathering and warning/surveillance capabilities are limited’ due to the lack of Pacific-facing radar stations and other early-warning platforms.^[11] In light of these limitations, the document indicates that Japan’s strategy will henceforth prioritise strengthening early-warning and information-gathering capabilities that can operate under all conditions, as part of a broader effort to strengthen defensive capabilities in the Pacific theatre. Another interrelated priority is a focus on capabilities that enable activities across a wide area (a key consideration given the sheer size of the Pacific), with boosting functions provided by close cooperation with partners and allies across the region. The objective of all this is outlined as ‘safeguard[ing] the necessary foundation not only of the SDF’s activities, but also of the continuance of [Japan]’s socio-economic activities’.^[12]

Analysis

The choice of the Ukraine conflict as a model case study is instructive of the kind of conflict Japanese planners envisage their involvement in, as it alone, among all ongoing global conflicts, sees a relatively weak country employ integrated air and missile defences which natively integrate both drones and missile systems against a far stronger adversary in control of a portion of its territory. The ongoing Iran–US conflict may have occurred too late to influence Japanese strategists. Still, its unfolding only serves to verify the fundamental soundness of their direction of thought: Iran has also used missile and drone systems concurrently to inflict substantial pain on its adversaries, while the closing of the Straits of Hormuz is a classic example of Anti-access/Area Denial for which countermeasures need to be deployed.

India’s role in the emerging strategy, as a potential site for fruitful cooperation, is also becoming clearer. Tokyo’s emphasis on sea-lane security across the Indo-Pacific makes clear a growing Japanese interest in securing the Indian Ocean, from West Asian resource hubs to its own ‘near seas’. India’s role as the region’s security partner of choice would be an obvious candidate in this regard.

In 2025, Defence Ministers from both sides discussed a new initiative, India–Japan (Japan–India) Defence Cooperation in the Indo-Pacific (IJDIP/JIDIP), which specifically listed ‘deeper collaboration’ in Southeast Asia as one of its objectives.^[13] The initiative has not been further fleshed out in the months since. If Japan sticks to the course outlined in the recently released document, it could be the perfect opportunity to add much-needed muscle to IJDIP.

Areas of collaboration, including regional maritime domain awareness, intelligence-sharing, and even joint technology development and demonstration, are ripe for further exploration. India’s role as a cost-effective production hub for certain varieties of dual-use equipment for Japanese defence manufacturers could also satisfy the procurement requirements identified in Japan’s security planning. Overall, the new policy signalled by Japan could present an invaluable opportunity to accelerate India–Japan security ties further.

^[1] Jesse Johnston and Gabriel Dominguez, “With Fresh Mandate, Japan’s Takaichi Sets Sights on Divisive Security Goals”, The Japan Times, 22 February 2026.

^[2] “第５回　防衛力変革推進本部” [Fifth Meeting: Headquarters for the Promotion of Changes in Defence Capability], Ministry of Defense, Government of Japan, 12 March 2026.

^[3] “防衛力の変革の方向性①” [Directions of Change in Defence Capabilities 1], Ministry of Defense, Government of Japan, March 2026, p. 2.

^[4] Ibid., p. 3.

^[5] Ibid., p. 4.

^[6] Ibid., p. 6.

^[7] Ibid., p. 7.

^[8] Ibid., p. 8.

^[9] Ibid., p. 10.

^[10] Ibid., p. 11.

^[11] Ibid., p. 12.

^[12] Ibid., p. 13.

^[13] “Japan-India Defense Ministerial Meeting”, Ministry of Defense, Government of Japan, 5 May 2025.