Japan’s Chief Cabinet Secretary Yoshihide Suga 8 Sept said Tokyo remains “seriously concerned” about Beijing’s intentions and “will respond in a calm and resolute manner” to any future Chinese intrusions on Diaoyu/Senkaku islands, which Japan controls but both countries claim. Japan increased vigilance after Chinese bombers flew off Kii Peninsula for first time 24 Aug, scrambling fighter jets even though Chinese aircraft did not enter Japanese airspace; Beijing asserted drills were normal and in accordance with international law, said no amount of interference or shadowing would prevent long-range exercises from continuing. Japan expressed concern through diplomatic channels. Two U.S. air force B-1B bombers and two Japanese F-15 fighters 9 Sept conducted drill over East China Sea. Japanese PM Abe and Indian PM Modi 13-14 Sept reaffirmed bilateral security and infrastructure collaboration, agreed to expand three-way joint military exercises with U.S.. Beijing 8 Sept hosted high profile ceremony commemorating 45th anniversary of normalised ties with Japan involving some 300 prominent figures from both countries; Abe attended ceremony at Chinese embassy in Tokyo marking anniversary and China’s national day 28 Sept, first PM to do so in over a decade, invited Chinese President Xi to visit Japan; Chinese and Japanese premiers exchanged congratulatory messages 29 Sept.

Japan 1 Aug said it had lodged diplomatic protest with Beijing calling for halt to China’s deployment of drilling rigs in gas fields near median line between their exclusive economic zones (EEZs) in East China Sea; same day urged China to resume negotiations on joint development of area. Tokyo argues boundary has not been finally determined; China, which reportedly has sixteen structures in area and rejects Japan’s concept of median line, retorted that areas are indisputably under its jurisdiction. Japan’s Air Self-Defence Force 15 Aug held joint drill with U.S. Air Force bombers near disputed islands. Chinese Foreign Minister Wang Yi 7 Aug met with his newly-appointed Japanese counterpart Taro Kono on sidelines of foreign ministers’ meetings in Manila. Wang said confrontation between the two nations harms interests of both as well as regional peace and stability, urged Japan to play more constructive role; Kono said Japan likewise wants to resume dialogue and improve relations. Japan’s defence ministry 8 Aug released annual white paper taking harder line on North Korea’s missile development program and concerns about China’s maritime military activities; China called latter statements groundless.

Chinese President Xi and Japanese PM Abe held cordial meeting 8 July on sidelines of G20 summit, reaffirmed importance of improving bilateral relations as their countries marked 45 years of diplomatic relations. Building on recent supportive statements, Abe reportedly called China’s Belt and Road Initiative “vision with potential”; Xi welcomed Japan’s participation. Xinhua news agency reported Xi said Japan should honour words on historical issues (i.e. apologies related to World War II) and Taiwan, improve situation in East China Sea, stay out of disputes in South China Sea, and remove all “distractions” in bilateral relations. Abe invited Xi to make what would be his first official visit to Japan in 2018. Planned trilateral China, Japan and South Korea summit postponed.

Month saw indications that both sides are working to downplay frictions over East China Sea (ECS) dispute. Japan and China held seventh High-Level Consultations on Maritime Affairs in Fukuoka 29-30 June, agreed inter alia to launch air and maritime contact mechanism as soon as possible; coast guards agreed to strengthen communications to enhance trust. Highlighting point of friction, four Chinese coast guard boats sailed into disputed ECS waters 24 June, prompting Japanese protest. China’s top foreign policy official, State Councilor for foreign affairs Yang Jiechi, visited Tokyo 29-31 May, met with PM Abe who reportedly told him Japan and China should work to improve relations from big-picture standpoint. Chinese state media reported Yang told his counterpart he hoped that Japan could meet China half-way, make efforts to build trust and move bilateral relations back to normal development track. Japanese media 6 June reported that Japanese officials floated idea of reciprocal visits by Presidents Xi and Abe in 2018, which would be first visit by Chinese president since 2008. Abe 5 June said Japan ready to cooperate with expression of interest in China’s Belt and Road Initiative under certain conditions. Tokyo and Beijing reportedly discussed more high-level meetings, starting with possible bilateral meeting on sidelines of July G20 summit in Germany and meeting in Aug between countries’ ruling parties “to exchange views on how to increase communication and strengthen economic ties”.

Head of U.S. Pacific Command Admiral Harry Harris 17 May paid first visit to new Japanese radar station on edge of East China Sea (ECS), 150km south of disputed Senkaku/Diaoyu Islands; Beijing expressed strong concerns. U.S. Navy conducted two simultaneous bilateral exercises with Korean and Japanese naval forces 25-26 April in first such peacetime deployment under new expanded security legislation, Japan sent helicopter destroyer to escort U.S. supply ship transiting its waters. China sent four coast guard vessels through territorial waters around Senkaku/Diaoyu Islands 30 April-8 May; repeating visit 18 May, China deployed drone over islands for first time, prompting Japan to scramble F-15 fighter jets. Japan’s coast guard said this was thirteenth Chinese intrusion in contested waters in 2017, compared with 30 in total in 2016. Tokyo lodged protests, accused China of “escalating the situation unilaterally”. Two Chinese SU-30 fighter jets 17 May made what U.S. Air Force called “unprofessional” intercept of U.S. surveillance aircraft tasked with detecting radiation over seas between China and North Korea. U.S. said it was discussing incident via diplomatic and military channels under bilateral military maritime consultative agreement. China’s defence ministry denied encounter was problematic, blamed recurrent U.S. reconnaissance near its territory.

Japanese Ministry of Defence 13 April reported its air force had scrambled jets against foreign aircraft approaching its airspace a record 1,168 times April 2016-March 2017, 295 more than the previous year; 70% of incidents were in response to Chinese military jets in East China Sea (ECS). Foreign and defence ministers of Japan and Australia met 20 April, agreed to “powerfully promote” trilateral defence cooperation involving U.S.. Japanese govt late March announced plan to populate disputed Senkaku/Diaoyu Islands in ECS and designate them inhabited border territories, important in defining size of its Exclusive Economic Zone (EEZ); plan includes building civic facilities, purchasing land, improving ports and preventing foreign vessels from illegally visiting; will similarly designate further 143 remote islands around its archipelago. Taiwan 2 April stated it has right to conduct oceanographic research within EEZ that both it and Japan claim.

China 23 March warned U.S bomber it was flying illegally inside its East China Sea (ECS) air defence identification zone (ADIZ) and said U.S. should respect zone; U.S. rejected Chinese position, said flight operations in region would continue. U.S. and Japan early March conducted joint military exercises in ECS.

China responded negatively to U.S. show of support for Japan during month. During visit to Japan U.S. Sec Defence Mattis 4 Feb reaffirmed commitment to defence treaty with Japan, reiterated that it covers disputed Senkaku/Diaoyu islands; also praised Japan’s increased military spending. China responded 4 Feb reaffirming its sovereignty over islands, accused U.S. of risking stability of region with its stance on islands. Three Chinese coast guard vessels sailed near disputed islands 6 Feb, fourth such patrol in 2017, prompting Japan to issue official protest. Japanese PM Abe visited U.S. 10-12 Feb; at joint press conference 12 Feb President Trump said U.S. “100%” behind “great ally” Japan; leaders issued joint statement confirming that Article 5 of U.S.-Japan security treaty covers disputed islands. Beijing 13 Feb expressed concern over statement, reaffirming that islands were China’s “inherent territory”. On sidelines of G20 meeting 17 Feb Chinese FM Wang Yi told Japanese counterpart Tokyo’s “negative” moves are preventing improvement in bilateral ties. Media 17 Feb reported undisclosed sources saying Japan plans to accelerate warship-building program to produce two additional frigates annually to patrol ECS. Japanese govt sources 26 Feb said Tokyo has doubled from two to four number of fighter jets it scrambles in response to incursions by foreign planes into its airspace.

Japan 9 Jan scrambled fighter jets after Chinese air force bombers and reconnaissance planes flew through Tsushima Strait over ECS and Sea of Japan – but not entering Japanese air space – for first time since Aug 2016; Chinese media accused Japan of overreacting. Japan reported Chinese coastguard ships temporarily entered Japanese waters around disputed Senkaku/Diaoyu islands 4, 8 and 22 Jan. Japan 24 Jan launched first military communications satellite to boost Self-Defence Forces’ capacity in region. During mid-month visit to Philippines, Australia, Indonesia and Vietnam, Japanese PM Abe discussed need for security and economic cooperation.

Chinese defence ministry 10 Dec said it had lodged representation to Tokyo over Japan’s interference with six Chinese military aircraft flying through Miyako Strait toward Western Pacific in what it called routine exercise; said two Japanese fighter jets scrambled Chinese aircraft from close range in “dangerous and unprofessional” manoeuvres counter to freedom of navigation and over-flight. Tokyo 12 Dec denied close-range interference, said Chinese statement “extremely regrettable and harms improving ties”, lodged protests; said Chinese aircraft did not violate Japanese airspace. Chinese air force 15 Dec said flybys through Miyako Strait in early Dec and late Nov “regular”, similar operations would become routine. Negotiation over bilateral Maritime and Air Communication Mechanism to manage such encounters continued with little concrete progress. At 9 Dec talks China and Japan agreed to launch contact mechanism at early date. Japanese PM Abe 21 Dec announced Japan would strengthen its coast guard in ECS to defend disputed Senkaku/Diaoyu islands; govt next day approved record high defence budget of $43.6bn.