What is a unique characteristic of the Trident II Intercontinental Ballistic Missile (ICBM)?

The Trident II Intercontinental Ballistic Missile (ICBM) is notable for its capability to reach incredibly high speeds, specifically up to 20,000 feet per second. This high velocity is crucial for its strategic role in deterrence, as it allows the missile to travel quickly through the atmosphere and reach targets at great distances in a short amount of time. The speed enhances the missile's effectiveness against enemy defenses due to the reduced response time they would have.

The other characteristics mentioned do not accurately describe the Trident II. Its propulsion system comprises solid rocket motors rather than a two-stage or liquid propellant system, and it is designed to target both land and sea targets, making it versatile in its military applications. Thus, the unique speed capability of the Trident II stands out as its defining characteristic.