Answer: They lost what they fought to preserve.
Step-by-step explanation:
The French and Indian War broke out in 1754 and then two years later, became part of a the wider Seven Years War. It was fought by the British colonies and Britain against the French colonies and their Indian allies.
The British invested huge sums of money into this campaign as they sought to hold on their American colonies and in the end won.
They then however, engaged in practices that sought to extract the war debt they accumulated by defending the colonies from the colonies themselves. This led to such widespread discontent that the American Revolution broke out which saw the British then losing their colonies.
It was ironic because the British feared losing their colonies to the French but instead lost their colonies by their own actions instead of those of the French.