When Prime Minister Shinzo Abe shifted Taro Kono from the foreign minister to defense minister billet in last month's Cabinet reshuffle, he was attempting to limit the influence of a potential successor. Abe could not push Kono out altogether, but the operative assumption was that the Defense Ministry, institutionally the weakest of all ministries in the government, would be a place to keep Kono's influence in check. The issue for Abe is that this inadvertently put the defense minister position in uncharted waters.

Kono is unlike any defense minister Japan has ever had. His political strength, his high profile, his personal and professional background, and his independent thinking on policy, set him apart. For the first time, the Defense Ministry is headed by a prime minister-ready politician, and that will lead to a unique, possibly precedent-setting tenure for this defense chief.

Although Kono will be limited in just how far he can exercise the authority of his new position, his political aspirations means he will leverage his responsibilities in ways that increase his public support, will demonstrate strong leadership in fostering relationships with foreign militaries, and will likely test the boundaries of how far he can go in pursuing policy objectives that may differ from the prime minister's personal defense agenda.