North Korea's Submarine Missile Launch a Bad Sign for US and Allies

North Korea's communist regime fired a ballistic missile from a submarine Wednesday.

The missile flew about 310 miles, the longest flight ever by the North for such a weapon,  before crashing into the Sea of Japan.

That range places all of South Korea, and possibly parts of Japan, within its striking distance.

"North Korea's nuclear and missile threats are not imaginary threats any longer, but they're now becoming real threats," South Korean President Park Geun-hye said of the launch. "Those threats are coming closer each moment."

In a rare display of unity, the foreign ministers of China, Japan and South Korea put aside their disputes to come together with sharp criticism of the submarine missile test.

North Korea already has a variety of land-based missiles that can strike South Korea and Japan, including U.S. military bases in those countries.

But the North acquiring reliable submarine-launched missiles is a worrying development because they are harder to detect before liftoff.

In June, North Korea, sent a midrange ballistic missile more than 870 miles high. Analysts say the high-altitude flight meant North Korea had made progress in its push to be able to strike U.S. forces throughout the region.

About 28,500 U.S. troops are based in South Korea to help deter potential aggression from North Korea, a legacy of the 1950-53 Korean War, which ended with an armistice, not a peace treaty.

U.S. troops are conducting their annual joint military exercises with South Korea now. North Korea usually responds to these South Korea-U.S. military drills with weapons tests and fiery warlike rhetoric.