Prime Minister Shinzo Abe, pressed by China and seeking to strengthen ties with the U.S., is considering Japan's biggest change in military engagement rules since World War II.

Barred by the traditional interpretation of the pacifist Constitution from protecting other nations' troops, the 59-year-old Abe says Japan needs broader deployment abilities.

Having increased the defense budget two years running and set up a U.S.-style National Security Council, Abe is now seeking to allow Japan to come to the aid of its allies, telling the Diet last month that "it's about whether we can exercise this right that every country has."