Will North Korean missile tests help to unify Asia?

South Korean officials said on Wednesday that a ballistic missile fired from a North Korean submarine near the coastal town of Sinpo traveled more than 300 miles before landing in the Sea of Japan, in what would be the longest distance achieved by the North in missile tests to date. 

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

The launch follows a June test that sent a ballistic missile more than 870 miles high before falling into Japanese territorial waters. But the latest test suggests that by using its submarines, the North could strike parts of Japan, including US military bases on Okinawa Island, adding to its preexisting capacity, which includes the entirety of South Korea.

It also occasioned a rare show of unity between South Korea, Japan, and China, reported The New York Times, as foreign ministers from the three East Asian powers gathered in Tokyo for previously scheduled meeting.

"We all know that on days when North Korea doesn't test missiles, tensions may be above the surface," said Scott A. Snyder, senior fellow for Korea studies at the Council on Foreign Relations. "But longer term, if you're looking for conditions that would suggest real stability in the region, that is the sort of cooperation that would be needed."

Wednesday’s launch came two days after the United States and South Korea began joint military drills, which the allies conduct annually over a two-week period – to the intense displeasure of the North, which views them as a rehearsal for invasion. It has also ramped up its saber-rattling after the US and South Korea reached an agreement to implement a missile-defense system in the South.

That agreement has caused discomfort in China, which shares a border with North Korea, because it feels it expands US capabilities of monitoring Chinese missiles. Upon announcement of the agreement, China's foreign ministry called it "no good for the stabilization of the peninsula," while its ambassador to Seoul warned that it would "create a vicious cycle of Cold War-style confrontations and an arms race," according to the Los Angeles Times.

In Tokyo on Wednesday, Chinese Foreign Minister Wang Yi reiterated opposition to the missile-defense system in South Korea, but echoed his diplomatic counterparts in saying that China "opposes development of North Korea’s nuclear program, and any words or deeds that create tensions in the peninsula," according to The New York Times.

In Japan, where the military began training on Wednesday for expanded capabilities granted by controversial recent reforms, Prime Minister Shinzo Abe denounced the launch as an "impermissible and outrageous act," according to the Associated Press. US Strategic Command said that the launch posed no threat to North America, but added that the US military "remains vigilant in the face of North Korean provocations."

This report contains material from the Associated Press.