Japan has spent the past 20 years trying to persuade the rest of the world to take a more critical stance on China. But having achieved that goal — with an increasingly hostile response from the US and its allies to a new national security law in Hong Kong — Tokyo is taking a back seat.

While the US, UK, Canada and Australia have suspended their extradition treaties with Hong Kong, and Washington has threatened sanctions, Japan has restricted itself to expressions of concern about the imposition of a law that diminishes Hong Kong’s freedoms and autonomy.

That approach, according to diplomats and analysts, reflects the impracticality of Japan decoupling from its powerful neighbour, and illustrates how difficult it will be for Washington to create the alliance it wants against Beijing.