TOKYO A deafening wail blared out in Oga, Akita Prefecture, in the northern part of Honshu, Japan's main island, at 9:33 a.m. on March 17. It was a siren meant to warn of an impending attack on the country.

But it was only a test. The high-pitched metallic sound was part of an evacuation drill conducted on the assumption that a missile had been fired and landed in Japanese territorial waters off the Oga Peninsula. The siren was followed by a male voice that warned: "Attention. Evacuation alert. Immediately take shelter as a missile may have been fired. Go inside, as parts of the missile may fall." Some 110 participants in the drill, including 44 students at Hokuyou Elementary School, fled to the municipal school's gymnasium and the local community hall in about 90 seconds.

Earthquake, tsunami, fire and other disaster drills have been conducted in various parts of Japan since the end of World War II. But it was the first time a drill has been held assuming an attack by a foreign country. The warning siren was also used for the first time.

The Japanese government conducted the new evacuation exercise as North Korea has been stepping up its provocations, including launching more than 20 ballistic missiles in 2016 alone. On March 6, furthermore, North Korea fired four medium-range ballistic missiles that landed in the Sea of Japan, three of which reached points 300-350km off the Oga Peninsula, within Japan's exclusive economic zone.

The government used to maintain that the deterrence of the Japan-U.S. alliance can forestall attacks by North Korea and that the Japanese Self-Defense Forces' missile defense system can intercept missile attacks.

But the North Korean missile launches in August and September last year demonstrated a considerable improvement in their striking accuracy, increasing the risk that some missiles could slip through the Japanese defenses if many of them are fired at a single target at the same time.

Faced with the heightened risk of such a "saturation attack," recognition has spread within the government that the missile defense system is not enough to protect the country from missile attacks. So multilayered preparations, including evacuation drills, are necessary. The drill in Oga was the first of this kind.

The drill was planned by Atsushi Odani, a counselor at the Cabinet Secretariat, who said, "We will call on other local governments to conduct drills based on lessons learned from the latest exercise."

Students at Hokuyou Elementary School join an evacuation drill in Oga, Akita Prefecture. (Photo by Tetsuro Kosaka)

The government will seek to cut the time from the detection of a missile launch to issuance of warnings to completion of evacuations through repeated drills. It is reported to have already picked a number of possible locations for the next drill.

Japanese defense authorities have also quietly drawn up scenarios for ballistic missile attacks by another country, namely a surprise attack by China.

WORST-CASE SCENARIO If it came to that, the Chinese military could fire DF-21 and other medium-range ballistic missiles with conventional warheads, targeting Japanese air bases, radar facilities and other SDF installations in Okinawa, Kyushu and other places in southwest Japan. As they have the accuracy to strike within around 10 meters, runways at the air bases could be destroyed within 10 minutes, making it impossible for aircraft to take off and land.

Chinese forces would thus gain air mastery over the East China Sea and freely attack and destroy ships of the Japanese Maritime Self-Defense Force and the Japan Coast Guard with missiles. This would enable its forces to land on Japanese islands.

While the attacks would be completed within a short time, the Chinese military would not attack U.S. forces stationed in Japan.

"If the Chinese forces move, they will target not only the Senkakus but also the Sakishima Islands, such as Miyako, Ishigaki and Yonaguni" in Okinawa Prefecture, at the southernmost end of the Japanese archipelago, the official said.

If China gains control over the islands, it could use them as beachheads for possible attacks on Taiwan.

In case of a Chinese invasion, U.S. forces are expected to step in under the Japan-U.S. security treaty. But "we are afraid that if the U.S. forces happen to be fighting in other places such as Europe or the Middle East, and if the U.S. government does not want to open a new battlefront in Asia, a Chinese invasion of the Nansei Islands may become accepted as a fait accompli, as in the case of Russia's occupation of Crimea," the official said.

Japanese Prime Minister Shinzo Abe shook hands with U.S. President Donald Trump for 19 seconds during their meeting in February. Abe said the long handshake was a message to China, especially the Chinese military, that there is "no gap to exploit" in the Japan-U.S. relationship.

But concern remains among Japanese government officials about a possible surprise attack if U.S. forces are preoccupied with armed conflicts in other areas.

NEW MISSILE STRATEGY Japanese defense officials and others have begun to discuss a new strategy.

"Weapons with fast response are needed to forestall possible sudden Chinese missile attacks and invasion of the Senkaku Islands," said a person well-versed in Japan's defense equipment policy. "They are medium-range ballistic missiles."

If Japan had such missiles, and China were to fire a large number of missiles at Japan and deploy aircraft toward the Senkaku and Sakishima islands, Japan could launch ballistic missiles at military targets in China within a few minutes, according to the policy expert. China would be forced to change its deployment plans if its runways were destroyed.

Even if Japan did not retaliate with missiles, its readiness to fire them would complicate calculations on the part of the Chinese military and would at least deter an invasion.

Cruise missiles and jet fighters cannot ensure a quick response due to their relatively slow flying speed.

The U.S. cannot stock medium-range ballistic missiles, as it has concluded an agreement with Russia to eliminate all medium-range nuclear weapons. Japan thus cannot expect the U.S. to play a role in this area of defense.

In terms of technology, ballistic missiles are almost identical to space rockets. Japan could quickly develop its own ballistic missile by modifying its existing rockets, which are known for their reliability.

Conducting evacuation drills against missile attacks and talk of Japan possessing ballistic missiles represent a world completely different from what the Japanese people have known to date. A change of such magnitude stems from the undeniably greater missile threats from China and North Korea.

It remains to be seen whether Japan can sufficiently prepare for possible emergencies in the future.