Barry Bull
Donor
There is only so many resources for the UK around the world and facing both Germany, Italy and Japan just stretched things very thin. If it's a Anglo-Japanese War, HK should be defensible.
Let’s consider the issue in two drastically different scenarios, these *do* require Japan to be even crazier than OTL, but help us to consider the question in a new way:
What if the Anglo-Japanese crisis over the Tianjin incident escalates to Anglo-Japanese War by summer 1939?
I would assume Japan's first targets would be any and every British enclave along the China Coast, treaty ports in China and Hong Kong alike.
Could the British reinforce Hong Kong (or indeed any of its other China enclaves) in time to hold back the Japanese? I don't know, but maybe. Maybe there could be a chance for successful Chinese-British coalition operations in South China including Hong Kong in this 1939 scenario.
Or, what if in the summer or fall of 1941 the Japanese invaded the Soviet Union instead of striking south?
Hong Kong will be left alone if Japan is still hoping for the British to be neutral in the Soviet-Japanese War.
And in a Soviet-Japanese war, British forces in Hong Kong, China and the Far East in general would be too small to do serious damage to the Japanese at the outset. So the British may stay neutral for awhile if given a choice by the Japanese.
But the British may want to reinforce, and without Singapore and Malaya under attack, may be able to trickle more stuff to the garrison. And if they plan to declare war on the Japanese they would reinforce.
If the Soviet-Japanese war begins, it would force a cutback in Japanese offensive operations in China proper, and would suck in more and more of the Japanese ground power and air power in China proper over the ensuing weeks and months.
That sets conditions for a potential effective defense of Hong Kong by the British, relief of Hong Kong by the Chinese, or some effective Sino-British coalition ops in China in general.