Last Thursday, the United States Navy announced that it had successfully carried out four Trident II D5 sub-launched ballistic missile test flights launched from an Ohio-class submarine over the course of a three-day exercise. The tests were conducted to evaluate the missile’s reliability and performance in a normal operating environment. While the Navy claims the tests “were not conducted in response to any ongoing world events,” the tests follow a North Korean KN-11 test and the Russian deployment of a ground-launched cruise missile system in violation of the Intermediate-Range Nuclear Forces (INF) Treaty last week.
Navy flight-tests sub-launched Trident II ballistic missiles – UPI
U.S. Navy test fires Trident missile as tensions heat up with Russia and North Korea – Military Times