Rikki Kersten was recently a guest of Japan's Ministry of Foreign Affairs to discuss security policy with Japanese policymakers.

While Tony Abbott has faced his leadership crisis over the last week, the policy ground has shifted underneath Japan's defence and security policy-makers. The 9 February announcement from Defence Minister Kevin Andrews that Australia's procurement of submarines will be subject to a 'competitive evaluation process' will have intensified those political reverberations in Tokyo.

While Australians feast on a domestic political spectacle, Japanese voters are contemplating the ruination of a carefully calibrated yet contentious strategy developed byJapan's defence and security policymakers. Events in Canberra could undermine the Abe Government's ambition to catapult Japanese defence thinking into a new paradigm which sees Japan as a global defence actor.

The joint development of Australia's next generation of submarines has acquired both a symbolic and a substantive significance for Japan's ambitious cadre of security policymakers.

In both Australia and Japan, the close security ties that have been expanding and consolidating since the 2007 Joint Declaration on Security Cooperation have become the personal crusades of prime ministers Abbott and Abe. As both leaders see it, closer security ties build on the 2014 Economic Partnership Agreement and represent the future of the bilateral relationship. The submarine collaboration that has been mooted by the press, explored by bureaucracies and flagged by ministers in both countries represents the commitment of both leaders to this shared vision.

For Japan, the symbolic significance of a submarine collaboration lies in the fact that Australia is not the US. Australia is seen as a benign, reliable and well-disposed partner that has moved beyond memories of World War II atrocities and into a future-focused friendship. It is the template for how Abe wants Japan's foreign relations to be. Importantly, Australia's status as a democracy and a middle power lend a normative patina to the relationship; Abe has already shown that he wants to emphasise the stark contrast between democratic Japan and undemocratic China. Australia gives credibility to this signaling display.

The substantive importance of a submarine deal for Japan lies in the rapid-fire policy changes scheduled to unfold in 2015–2016.

Driven by Prime Minister Abe's personal commitment and ambition, the acceleration of security policy innovation in Japan was already evident when, in July 2014, the Abe cabinet passed its resolution re-interpreting the constitution to affirm Japan's right to collective self-defence. Abe's security bureaucrats have since been working on a suite of legislation to underpin this stance. These laws are to be submitted to the Diet in the summer session from May onwards.

This policy ambition was jolted into a state of urgency when the second Japanese hostage was murdered by ISIS.

Popular reactions to the murder of Kenji Goto have exposed a chasm in public attitudes towards new security policy in Japan. Those who want Japan to shed self-imposed restraints and enable Japanese forces to rescue hostages abroad want a permanent bill passed to that effect. Those who recoil from this argue that if offering even non-military assistance to nations combating ISIS invites such horror, Japan should abandon 'proactive pacifism' altogether. They argue that moving closer to the US and shouldering more responsibility in the US alliance is not in the national interest in this world of global terrorism.

This is a nightmare scenario for Abe, who wants to decisively end the post-war shackling of Japan so that it can be a 'normal' defence actor. Being trusted by a nation such as Australia with defence procurement is a vital emblem and foundation stone for Abe's ambitious agenda for 2015.

Without Australia as a substantive partner, and without Abbott in his corner, Abe may find it difficult to persuade even his own coalition partner, the Komeito, to sign up to his legislative agenda, let alone the Japanese voting public. Already leery of messing with the pacifist clause of the constitution, the Komeito will not risk alienating its support base before the April 2015 round of nation-wide local elections by openly supporting contentious security policy changes, including constitutional revision, which is also on Abe's agenda for 2016. Australia's presence in the policy landscape would have softened the message for them too.

Collaborating with Australia on submarines offers an anchor of stability and trust for Abe as he persuades observers at home and abroad that Japan's trajectory towards defence normalisation is legitimate and achievable. The tribulations of a first term Abbott administration have added another complication to an already herculean task for his partner Abe that may stymy the evolving potential of this bilateral security relationship.