Japan's proud pacifism has been rocked as if by an earthquake. Prime Minister Shinzo Abe's cabinet has ignored the majority of Japanese and the concerns of China and other Asian countries by deciding to end a ban on troops fighting overseas. The move is a landmark, both for its disregard for the constitution, the nation's people and the region's sentiment about Japanese war-time aggression. It is a regrettable step that will only worsen relations with neighbours. With most Japanese opposing amending the pacifist constitution, Abe instead opted for a reinterpretation of Article 9, which limits the country to defending itself in a conflict. Successive governments have taken this to mean that defending another country when Japan is not threatened would be unconstitutional. The decision, to be approved by parliament, but largely a formality given the coalition government's strength, will end the ban on "collective self-defence". The change means Japanese soldiers could fight abroad to help an ally and limits on participation in UN peace-keeping operations would be relaxed. Reinterpreting Article 9 furthers Abe's militaristic and nationalist agenda. He has made strengthening Japan's armed forces a priority since taking office 18 months ago. His right-wing government has already formulated a new national security strategy, increased military spending with each budget and abandoned a long-held ban on arms exports. The goal is to protect overseas interests, broaden military cooperation with top ally, the US, and, most worryingly, be able to be more militarily assertive in defending islands disputed by China and South Korea. The US has welcomed the change - it has long wanted Japan to be more responsible for its own defence - but there is no positive side for Japanese and the region. It erodes the constitution and raises tensions. Lawmakers have to dilute the measures and lobby for a rethink. Rather than being provocative, Abe should, as a matter of urgency, promote dialogue with neighbours.