Japan's own "pivot" to East Asia has been on full display over the last two months as Tokyo's efforts to lay the foundation for a more proactive approach to countering Beijing's growing maritime assertiveness begin to bear fruit.

The flurry of recent activity in the region by Japan comes ahead of a Group of Seven leaders' summit in Mie Prefecture next month and a verdict by the Permanent Court of Arbitration in the Philippine case against China's "nine-dash line" claims to much of the disputed South China Sea.

Tokyo's ramped-up moves appear to be the culmination of months of plans, often made in conjunction with allies and other claimants to waters in the South China Sea, to ratchet up pressure on a recalcitrant Beijing.