Final answer:
Kaiser Wilhelm II made Britain nervous by challenging their naval supremacy, supporting an independent state in Morocco, and adopting an aggressive foreign policy.
Step-by-step explanation:
Kaiser Wilhelm II made Britain nervous through a series of actions and policies. One major cause of Britain's concern was Germany's ambition to build up its navy and challenge Britain's naval supremacy. Kaiser Wilhelm's support for an independent state in Morocco also caused tension, as it threatened Britain's colonial interests in North Africa. Additionally, Wilhelm's aggressive foreign policy and his belief that Germany was surrounded by hostile nations contributed to Britain's nervousness.