While it is true that the threat of the Japanese Empire was successfully ended, it inevitably spawned a dozen other problems in other scenarios.

By these standards, pretty much everything one does of any consequence in international relations spawns a dozen other problems.

As soon as you use "sufficient brutality" and prove yourself to be dangerous, you will prompt everyone else to become more dangerous.

Everyone else is quite capable and willing to become more dangerous without any prompting from us. Becoming dangerous is useful for its own sake, not just as a response to others being dangerous.