 The planners envisaged that a war with Japan would have three phases : while the garrison of Singapore defended the fortress , the fleet would make its way from home waters to Singapore , sally to relieve or recapture Hong Kong , and blockade the Japanese home islands to force Japan to accept terms . The idea of invading Japan was rejected as impractical , but British planners did not expect that the Japanese would willingly fight a decisive naval battle against the odds . Aware of the impact of a blockade on an island nation at the heart of a maritime empire , they felt that economic pressure would suffice . 
