For some people, this is a tautology. How could you be happy if you're not safe and how could you not be happy if you're safe?
For others, it's a contradiction. Safe is a good place to start from but how can one find happiness in safety? Safety is for the between times; between times of happiness.
Of course, most people are somewhere betwixt these two poles.
For me, I can summarize it in a quote: "A ship in harbor is safe — but that is not what ships are for." —John A. Shedd