How and why did the Germans go to such lengths to destroy Britians empire?

The Germans realized that the best way to defeat Britian on the western front was to threaten her colonial possesions. If Britians empire was at risk the British would stop at nothing to preserve it, therefore diverting troops from the main German objectives in Europe. Germany started the plan to attack the British empire by first attacking British South Africa then attacking India. Germanies colonies however, were also attacked and Conqured by the British and their allies. These colonies included possesions in China an German South-West Africa.