A causal pole-zero system is BIBO stable if its poles are inside the unit circle. Consider now

Question:

A causal pole-zero system is BIBO stable if its poles are inside the unit circle. Consider now a pole-zero system that is BIBO stable and has its poles inside the unit circle. Is the system always causal? Consider the system h1(n) = anu(n) and h2(n) = anu(n + 3), |a| < 1.