This week, Pope Francis made a historic visit to Hiroshima and Nagasaki. On Sunday, the pontiff was clear in his call for global nuclear disarmament, stating, "The use of atomic energy for purposes of war is immoral. ... As is the possession of atomic weapons."

This message resonated with the large segment of the Japanese public who vehemently opposes nuclear weapons and prompted a question to Chief Cabinet Secretary Yoshihide Suga about Japan's own reliance on the U.S. nuclear umbrella. Suga responded that the long-standing policy is "realistic and appropriate."

Suga's response may have been concise and resolute, but we are likely to see a revisiting of the nuclear weapons debate in Japan. The region has witnessed North Korea's development of increasingly devastating nuclear technology and more sophisticated delivery vehicles. Fears of U.S. abandonment will lead many to question whether Japan may indeed pursue its own nuclear arsenal — which is technically feasible given the country's technology and availability of nuclear material.