TOKYO - The prospect of Mr Joe Biden in the White House has eased Japan's worries over their security alliance but there are ripples of trepidation that the United States may become more conciliatory towards China.
Tokyo suffered fours years of apprehension as President Donald Trump took a transactional view of their defence treaty, and his impending departure has stirred expectations of a likely return of the US to multilateral institutions and greater respect being shown to bilateral alliances.
But there is a silent minority which sees Mr Trump as better for the region, given his hardline posture towards China. This conservative section thinks the engagement policy pursued by former US president Barack Obama, under whom Mr Biden served as vice-president, was a disaster.
Citing discussions with former diplomats, Dr Kiichi Fujiwara, who teaches international politics at University of Tokyo, says: "Facing China's rise is a high priority for Japan and there is a fear of a return to an Obama-era policy of engagement. Trump is tough and unpredictable but some believe that a mad man is better than a soft guy."
Still, there is hope that even as Mr Biden moves to mend ties with Beijing, he will put more faith in the US' alliance with Tokyo.
Dr Fujiwara adds: "Biden's approach to China would be, in many ways, just as hardline but the key difference is that he would try to mobilise support from allies."
In part emboldened by a more hawkish Washington, Japan has pursued tougher policies against China. Tokyo has, in its recent annual defence reviews, cited China as a greater security threat than North Korea.
Japan will effectively ban the procurement of Chinese-made drones for defence and infrastructure surveillance from next year, the Nikkei reported earlier this week.
It will also tighten inspection procedures in issuing visas for Chinese students and researchers over foreign interference fears, the Yomiuri reported last month.
On the other hand, given how inexorably linked the Chinese and Japanese economies have become, Tokyo cannot afford to entirely decouple from a country it views as its greatest security threat.
Japan is also hedging, with the realisation that, as an Asahi Shimbun editorial puts it, "an over-reliance on one major power is not a wise strategy in this new era".
Amid the US' waning global influence - a trend that Japanese media said began under Mr Obama who noted that "America is not the world's policeman" - Japan has sought to build closer ties with Europe, Australia and Asian nations.
There are calls for Japan to be the "sixth eye" in the Five Eyes intelligence alliance that comprises Australia, Britain, Canada, New Zealand and the US.
This week, as the US and Japan successfully test-fired a jointly developed intercontinental ballistic missile, Prime Minister Yoshihide Suga welcomed his Australian counterpart Scott Morrison in Tokyo.
The two leaders agreed on a bilateral defence pact to allow their troops to work more closely, in what is the first such arrangement for Japan since the 1960 status of forces deal with the US.
Dr Tosh Minohara, who chairs the Research Institute for Indo-Pacific Affairs, says it is a "cat-and-mouse game" with a risk of China, North Korea and Russia aligning together even more closely.
This reinforces the importance of Japan building partnerships and beefing up its own defence capabilities, he adds. "Unlike the US, Japan has no option of falling back (given its geographical location)," he says. "While Biden's election means it is generally back to business as usual, it does not mean that Japan can just sit back and not be proactive in engaging the US."