Why was Great Britain a problem for Napoleon?

Answer 1

Because the UK is an Island Nation with the English Channel acting as a giant moat between it and Europe. Napoleon lacked the Naval assets required to execute an Amphibious Operation. He could have built more ships, but he did not have adequate well trained sailors, gunners or a Naval Tradition. Even when he had a larger and more heavily armed fleet based on the Spanish Fleet being included, the Royal Navy cut him to pieces at Trafalgar.

Answer 2

Napoleon was aware that the only chance to decisively defeat Great Britain was that of

land there, smashing its inferior army and impose his conditions of peace in London.

But in order to succeed in that enterprise it would have been necessary conquest the control of the sea on the English Channel for a certain time, thus allowing the landing of a great French Army in the South of England, what was impossible to achieve.

Answer 3

Britain's Naval power was a constant threat to his dream of Empire.