Sustainability is important for a very simple reason: we cannot maintain our quality of life as human beings, the diversity of life on earth or earths ecosystems unless we embrace it. In order to have healthy communities, we need clean air, natural resources, and a nontoxic environment.
You might be talking about Franklin D. Roosevelt’s Infamy speech, given just after the pre-emptive attack on Pearl Harbor and the Philippines by the Empire of Japan. The short speech emphasizes on how Japan attacked the United States without first declaring war, and then declaring that the United States is ready to act and do measures for defense.
You have to compare to teacher to something else like: "My teacher is as sneaky as a fox" ; Something like that.
