Photo/IllutrationAn Air Self-Defense Force F-15 fighter (Asahi Shimbun file photo)

Japan is considering mounting long-range cruise missiles on Air Self-Defense Force fighters that can strike enemy vessels and even military installations in North Korea during emergencies, sources said Dec. 5.

The government has already decided to earmark research costs for the proposal in the initial budget plan for fiscal 2018, which starts in April. The Defense Ministry has conveyed the decision to executives of the ruling parties, they said.

However, the use of such long-range missiles could contradict the government’s policy of using the Self-Defense Forces only for the defense of Japanese territories.

Unlike ballistic missiles, which are generally launched from land or ships and travel in an arc-like trajectory, self-propelled cruise missiles fly at low altitudes.

The cruise missiles under consideration are the U.S.-developed JASSM-ER, with a range exceeding 900 kilometers, and the JSM, developed by Norway and with a range of more than 300 km.

Both types of missiles are fired from fighters.

The JASSM-ER would be mounted on the F-15, the ASDF’s mainstream fighter, while the F-35, the most advanced stealth fighter, would be equipped with the JSM, according to the plan.

“Both (missiles) are intended to defend remote islands,” a government official said.

However, the government also has in mind North Korea, which has continued advancing its nuclear weapons programs and has fired ballistic missiles over Japanese airspace.

With the introduction of the cruise missiles, the Abe administration intends to strengthen Japan’s defense capabilities and heighten its deterrence against hostile action by enemy countries.

When the Defense Ministry submitted its budget request for fiscal 2018 to the Finance Ministry in late August, it did not include research costs for cruise missiles.

As for carrying out a pre-emptive strike on an enemy base that is preparing to launch a ballistic missile, the government says such a capability is possible under the war-renouncing Constitution because it is within the limits of self-defense.

However, the government has not allowed the SDF to have that capability from the viewpoint that the SDF must be used only to defend Japanese territories.

In a Diet meeting on Nov. 22, Prime Minister Shinzo Abe suggested that the government will consider gaining the capability of attacking an enemy’s military bases.

“I have the responsibility to consider various measures based on the reality of what I should do to protect the people’s lives and peaceful livelihoods,” he said.