Although Great Britain might have had the greatest navy in the world during the 19th century, the British felt unprepared for an armed German invasion, especially after Germany's victory in the Franco-Prussian War (1870-1871). For that reason, Britain was concerned about France's defeat by Germany at the end of the 19th century, since British people thought they also might be attacked by the Germans. Germany was now seen as the Britain's potential new enemy because of its efficient as well as militaristic power.
The Declaration listed the colonists' thoughts about freedom and government and outlined the reasons why they thought the British were being unfair. Think of the Declaration of Independence as a letter to the British explaining that the colonies wanted to be 'free agents' and form their own team.