Weeks into the job, Japan’s new leader has come face-to-face with what it means to cross China’s red line on Taiwan.

Japan and China recently agreed to cooperate more economically. Now, climbing tensions are threatening that cooperation.

Tension between Japan and China has escalated over the new Japanese leader's suggestion Tokyo could intervene militarily if Beijing attacks Taiwan.

Beijing suggested it might reimpose a ban on seafood imports from Japan after warning its citizens to avoid travel there and postponing the releases of at least two Japanese movies.

Trade cooperation between China and Japan has taken a "great" hit following the recent remarks on Taiwan made by the Japanese prime minister, the Chinese commerce ministry said on Thursday.

Beijing is flexing its military and economic might to show its displeasure with the Japanese leader’s comments about defending Taiwan. But its aggressive approach risks backfiring.

China stepped up its economic war with Japan on Wednesday as a dispute between Asia’s two biggest economies intensified over a remark by Tokyo's new leader about a Japanese response to any Chinese military move against self-ruled Taiwan.