This is the sixth instalment of a series that focuses on Japan's security environment.
Early last month, a Maritime Self-Defence Force air-cushioned landing craft raised a spray of water while landing on a beach in the suburbs of San Diego. One after the other, armed Self-Defence Forces personnel and US soldiers disembarked from the craft, getting into a crouched position on the beach.
This was a Japan-US joint exercise dubbed "Dawn Blitz" that simulated the landing by SDF personnel and US soldiers to retake a remote island occupied by enemy forces.
On the minds of the SDF and the US military are the Senkaku Islands in Okinawa Prefecture, around which Chinese government vessels have repeatedly entered Japanese waters.
US Marine Corps Brig. Gen. David Coffman said the exercise simulates how the US military assists friendly nations that request support when they face unstable situations or regional threats.
The previous Dawn Blitz exercise in 2013, in which the SDF participated for the first time, was limited to a landing drill. The latest Dawn Blitz, however, was performed closer to combat conditions. In the exercise, a command centre was established after the landing, and equipment and food supply lines were secured. Preparations for the defence of remote islands, considered "Japan's contingency," have steadily been progressing.
What about responses to so-called gray-zone incidents (see below), which do not amount to a military contingency? Problems remain to be solved even after Diet debates over security legislation.
"We should ensure thorough territorial patrol operations near the country, rather than discussing the right of collective self-defence in places far away such as the Persian Gulf," Goshi Hosono, chairman of the Democratic Party of Japan's Policy Research Committee, said in the House of Representatives special committee on the security legislation on July 10.
Hosono criticised the government-proposed security legislation, which he said leaves an initial response to gray-zone incidents to police or the Japan Coast Guard. The DPJ insisted that the SDF be given police authority to a certain degree. The largest opposition party submitted jointly with the Japan Innovation Party a counterproposal to the Diet.
The government, however, rejected the counterproposal.
"If the SDF exercise police authority during peacetime, this could give the opponent [country] a pretext that it is the Japanese side that escalated the situation to the 'military vs military' level," Prime Minister Shinzo Abe said.
However, some members of the ruling parties believe the security legislation cannot fully respond to gray-zone incidents.
Since September last year, it has been found that many Chinese fishing boats poached a large amount of rare red coral around the Ogasawara Islands and the Izu Islands chain. At one time, more than 200 boats gathered around the islands, which shocked the Japanese people.
However, the JCG's response to the coral poaching by those Chinese fishing boats came too late because it was forced to operate on two different fronts. The JCG also needed to patrol around the Senkaku Islands. Many LDP members said during an emergency meeting that "the SDF should be mobilized."
However, the ruling parties did not review the authority of the SDF, police and the JCG. LDP Vice President Masahiko Komura, who chairs the ruling parties' panel on the security legislation, pointed out the difficulty in making adjustments in authority between the SDF and police.
"This is a 100-year war between the military and police," he said. "We'll be in trouble if we go deeper into the matter."
An issue related to the authority over the use of weapons was also left unaddressed. Even under the security legislation, when the SDF encounter a situation in which a ship does not obey an order to stop, they are only allowed to fire against the ship under the same conditions as the JCG.
However, the SDF can be mobilized after the government has ordered them to carry out a public security operation or maritime security operation only when the government has judged a situation as something that police and the JCG cannot deal with.
"It is possible to supplement the JCG in terms of quantity, but difficult to do it in terms of quality," said former MSDF Adm. Takashi Saito.
Is it possible to defend remote Japanese islands under such circumstances? There must be continuous discussions in the future over preparations for gray-zone incidents.
A gray-zone incident is a situation that cannot be deemed an armed attack, but in which tensions are higher than during peacetime. An armed attack is defined as "an organised and planned use of force based on the national will." If the situation does not amount to an armed attack, the Self-Defence Forces cannot be mobilized to carry out defence operations based on the self-defence right. In such a case, police or the Japan Coast Guard will primarily deal with such a gray-zone incident and the SDF will play a supplementary role.