Aizawa told a La Trobe University Asia seminar earlier this year Japan had concerns about the policies of US President Donald Trump and the unpredictability of his administration, which were changing Japan's traditional thinking on foreign policy.
"We tried to analyse the defence strategy of the Trump administration that came out this year,” he said. “What was in the text and what was in the speech is different … should we analyse very much the text or should we analyse the speech?"
Aizawa said the US seemed to put the security strategy first – with its emphasis on the threat posed by Russia and China – and America's alliances second.
Aizawa visited Australia before Trump vowed to impose tariffs on imported steel and aluminium and before the shock news the US President would personally meet North Korean leader Kim Jong-un for nuclear negotiations.
As The New York Times opined, just one of those two "improvisational decisions" would have unnerved American allies in Asia in a "dizzying jolt of drama that injected fresh uncertainty into strategic calculations in the region, where China is seeking to supplant the United States as the major power."
For his part, Aizawa said language which sought to "demonise" the politics of trade was very worrying to Japan because investment was its economic lifeblood.
Aizawa says Japan wants to minimise any power vacuum from a US retreat in Asia while building new alliances and multilateral arrangements.
This includes the nascent Quadrilateral security pact involving India, Japan, the USA and Australia and the TPP-11 (which is formally the CPTPP). There is also the planned Regional Comprehensive Economic Partnership (RCEP) based around the 10 ASEAN countries.
Aizawa says Japan wants to be inclusive in working with "strong partners" which were not necessarily democracies, such as Vietnam.
"There's a nuanced difference between who we are and who we work with, that's one modification we see over this past 10 years or so," he says.
"We see the importance of multilateralism … Japan is not a big country like the United States or China any more. So we have to be smart about our survival strategy and … multilateral platforms are even more important in coming decades."
As Aizawa puts it, the US has the strategic and military "tools" but Japan has "political weight".
"Japan is not the second largest economy as it was in the 80s and 90s. So you can’t be the champ. But if you want to a major player in the architecture, I think that is a very strong position," he says.
"Domestically in Japan, there is so much debate about all of these security issues that were taboo five years ago … I think that the Trump administration has given a wake-up call, not just for the [Japanese] government but also for the public as well."
Under Japan's tweaked pacifist constitution it can only deploy troops overseas under strict conditions. But it has to ensure vital sea lanes remain open – in the Pacific but also in an Indian Ocean vital for Japanese energy supplies.
"That's why India became a very important partner in the mix," Aizawa says. "This is a kind of new alert. The ocean is in the frontline of the strategic build-up. It’s not in the continental, it’s not in the archipelago, it’s the sea that matters."
Aizawa also stresses the importance of Taiwan, seldom mentioned in contemporary Australian political debate.
"That's one of the most important things that are missing in the Japanese debate as well," he says. "People are all eyes on the Korean peninsula but strategically speaking Taiwan is much more important."
Until recently, hawks in Washington were talking of giving North Korea a "bloody nose" which Aizawa says Japan flatly rejects. Instead he says Japan wants "normalisation" of relations without putting nuclear weapons "at the front" of the engagement process.
"It's not just that you demonise one family and you think it's over,” Aizawa says. “We don’t think that way. We have a longer term relationship that we have to work with … it's about more about community to community because in the end it has to be the normalisation."
Aizawa says progress on North Korea might take decades but offers an interesting comparison with Myanmar which, not so long ago, was also isolated from international society.
As he puts it, the leaders of Myanmar sought to keep their military power by democratising, albeit partially. Meanwhile the Kim family is trying to survive by militarising.
"Why is this different?” Aizawa says. “I think it’s very much the confidence is there … the confidence of survival."
"While the Kim family has low confidence in survival. I think that is going to be very dangerous … in the Myanmar case, the military was confident in retaining their power even though they democratised."
"Myanmar also had ASEAN, Myanmar had friends to give a cushion. You don’t have to face the international world order by yourself. … unfortunately in North Asia we don’t have ASEAN … we have China and we have the United States, it’s a different position."
"I think the key is how much the Kim family are confident and then try to convince them because we’re neighbours. We can’t try to muscle him out in a very militaristic way. We saw that in the Middle East … and we know what happened afterwards."
On the home front, Aizawa believes Japan's problems – a stagnant or low-growth economy and an ageing population - will produce a new generation of leaders who are not necessarily products of the political class and the Liberal Democratic Party machine.
He says this new breed will be more concerned with "livability" and the problems of urbanisation rather than only Japan's traditional emphasis on national economic development.
"A new leader in Japan who runs a local government also could be a very popular person to lead, and that kind of expertise is much needed in other Asian countries as well," Aizawa says.
"It’s a different challenge, a different risk … they have to deal, not just with the earthquakes and tsunami, but also a lot of environmental issues - sanitation, waste management … you have to clear the air, you have to clear the water."
"Japanese policymakers have struggled with this and on how to run social welfare systems, so this kind of expertise will be the incubator for new leadership, which is already the defacto kind of path to leadership."
Aizawa says Japan's experience in delivering a relatively high standard of living despite low economic growth will help it win deals in other Asian countries grappling with similar problems.
He says Japan learned a "big lesson" in 2015 when China used "no-strings" financing to clinch a deal to build a high-speed rail project in Indonesia, thwarting Japan's plan to export its famous Shinkansen high-speed railway system.
That lesson was high-quality engineering is important but so too is the financial engineering. And to perhaps not chase mega-projects like inter-city rail systems but rather intra-city subways.
"I think that what we’re now seeing in Hanoi, Ho Chi Min City and even in Manila," Aizawa says.
"The urbanisation issue is very important … the livability inside the city in a low-growth economy. I think that is something that Japan has to sell."
"All these rising, emerging powers in Asia will not have eternal development. There will always be time that they will slow down, which includes China as well."
For now, Japan is thinking hard on how face a risen China and a reduced US.
Mark Skulley is a regular contributor to BlueNotes. Jim Skulley wrote his honours' thesis at La Trobe University on Japanese security policy.