Kanehara served as assistant chief cabinet secretary from 2012 to 2019 under the administration of Prime Minister Abe Shinzo. During these years, he was involved in the foundation of Japan's National Security Council and served as its first deputy director until October 2019. He has been described as "a theoretical pillar of diplomacy at the Prime Minister's Office." He is currently a professor at Doshisha University.
He spoke to NHK about the current significance of the Japan-US security treaty, which marks its 60th anniversary this year.
Kanehara said he wanted to emphasize three points. On the stability of the East Asian region, he noted that China's economy is now three times larger than Japan's. China's military budget is four times larger. As a result, he said Japan cannot be a counterweight to stabilize the region alone, and it needs US commitments. "We have to work hand-in-hand," he said.
Kanehara's second point concerns the emergence of the liberal international order in Asia since the 1990s. He noted there are many new democracies in the region.
"We have to support this liberal order, freedom, human dignity, rule of law," he said. "These are things we have to defend together."
His third point touched on the free trade system. He noted that while the US is not part of the Trans Pacific Partnership at the moment, Japan wants it back in. He said free trade needs to be sustained and guaranteed. "We have to keep the ocean open to everybody," he said.
He called these three priorities the "three missions of the Japan-US alliance in this century."
Japan's government announced in June it would withdraw its plans for a multi-billion dollar missile defense system, known as Aegis Ashore. People living near the proposed sites strongly opposed the system over worries about the dangers posed by falling rocket boosters.
Kanehara says he supports the decision to withdraw the plan. He noted that there were concerns that falling boosters could threaten civilians. And even though some people had said it could be technically fixed, the costs and time to do so would have been prohibitive.
"So this was, I think, inevitable. This will be, and this is, the right decision," he said.
Following its withdrawal from the Aegis Ashore plan, the government now plans to rebuild its national security strategy, including its missile defense system.
Kanehara stressed that the security environment surrounding Japan is becoming increasingly severe. He said missiles have been proliferating around the region, and that Russia and China have very sophisticated missiles. He said North Korea may be borrowing technology from these countries to improve its own missiles. Meanwhile, South Korea and Taiwan have their own intermediate cruise and ballistic missiles.
"Now seems to be a missile age. Everybody has missiles. It's only Japan who is naked," he said. "The Americans have lots of missiles, of course, and they have a missile defense that's bulletproof," he added. "We only have bulletproof vests. So we have to change the priority a bit because missile defense is far more expensive than the missiles of our possible opponents."
Kanehara also said Japan must develop its offensive capabilities.
"The balance of offense and defense is very important," he said. "We have to put some priority upon offensive capabilities."
He said the division of labor between the US and Japan should be re-examined. He said the expression that Japan is the "shield," and America is the "spear," is long outdated.
"Everybody has lots of spears these days. So we have to prioritize our assets and find a new balance between offense and defense. And we have to do this in a complementary way with American forces."
The government says it will seek the most effective deterrence and response capabilities. Discussions within the ruling Liberal Democratic Party are expected to focus on having the capability to attack enemy bases. That would include the ability to strike an enemy missile base before it launches its missiles toward Japan.
The government has said it can have such capability under the Constitution, but would not have it as routine policy decision.
Some LDP members say the government should have this capability. But many members of junior coalition partner Komeito oppose the idea. Much attention will be focused on future discussions.
Kanehara said it's already past time for a discussion of attacks against the enemy missile bases — something that would have been appropriate for the 1950s.
"It's too narrow," he said. "This is a new missile age. We have to put this in a much broader context to perfect our deterrence."
Kanehara seems to be calling for a more comprehensive offense capability, with attacks not limited to missile bases — a so-called "integrated attack capability."
Japan is at a turning point, he adds, and must consider a dramatic change to its security policy.