As Japan and the U.S. work toward a historic upgrade of bilateral defense cooperation guidelines for the first time in 17 years, the biggest tasks for the two allies may be dealing with China's growing military and economic might while also keeping an eye on events in North Korea and its unpredictable leader.

In interviews with The Japan Times last week, Richard Myers, former chairman of the U.S. military's Joint Chiefs of Staff, and Takashi Saito, former chief of staff of the Joint Staff Council of the Self-Defense Forces, agreed that while the two allies have boosted their deterrence power, especially against China, more work should be done to counter nontraditional threats such as cyberattacks.

While China remains a big concern in the Asia-Pacific region for Japan and the U.S., both former officials admitted that neither country could contain Beijing, as the three nations remain economically interdependent.