>Dunkirk was a strategic retreat. No surrender there.
Dunkirk was an act of survival for the UK. If the Nazis had captured the BEF there the war would have been over.
>Singapore was indefensible without adequate air and naval support. In neither case was Britain defending its home turf.
UK forces screwed the pooch there. Japanese troops went overland without supplies to attack the city in the rear. However, it shouldn’t have worked. The Japanese force was a 1/4 the UK force and the city was heavily fortified. All they had to do was put a minor resistance and the Japanese army would have had to withdraw. But as typical in WW2 UK commanders were awful and turned what should have been an easy victory into a defeat.
Exactly. By the time the Japanese reached Singapore their army was in bad shape, exhausted, hungry and sick. There is a wierd myth that the Japanese were natural jungle fighters but this is completely untrue.