Despite the Defense Ministry's denial that the helicopter carrier Izumo, launched in 2015, was planned to be refitted into an aircraft carrier, former Maritime Self-Defense Force executives confirmed that that is how the blueprints were drawn up.

“It is only reasonable to design (the Izumo) with the prospect of possible changes of the circumstances in the decades ahead,” a then MSDF executive told The Asahi Shimbun. “We viewed that whether the Izumo should be actually refitted could be decided by the government.”

The former executive said a consensus was reached privately among the MSDF that the Izumo should be considered for conversion into an aircraft carrier. But the MSDF couldn't explain the need publicly due to the government's view that aircraft carriers capable of launching large-scale attacks are equivalent to the military capability prohibited by the war-renouncing Article 9 of the Constitution.

Ever since the Izumo's construction, experts both in and outside Japan have pointed out the possibility of turning it into a full-fledged aircraft carrier.

However, the Defense Ministry publicly denied any plan to deploy fighter jets with strike capabilities on the Izumo and contended that it was not an aircraft carrier.

The ministry has since done an abrupt about-face and now is mulling the possibility of refitting the vessel into an aircraft carrier.

Such a reversal has inevitably raised suspicions that the ministry had this plan in mind from the beginning.

Refitting the Izumo, the Maritime Self-Defense Force's largest vessel, into an aircraft carrier had been considered since late 2000 to bolster the nation's defenses against China’s increasing maritime advances around Japan’s southwestern islands, according to the MSDF executives.

Equipped with a flat deck from bow to stern, helicopters can land on and take off off from the five spots of the flight deck at a time. The Izumo's basic design was formulated from 2006 through 2008.

In 2008, Chinese naval vessels and other warships passing through the waters between the main Okinawa island and Miyakojima island, which lies to the southwest, were spotted for the first time. At that time Chinese government vessels intruding on Japan’s territorial waters became common.

According to MSDF executives at that time, the MSDF saw the need to secure Japan’s competitive edge in the airspace to counter possible China’s maritime expansion in the East China Sea.

However, the runway at the Air Self-Defense Force Naha Base is the only one that allows ASDF aircraft to take off and land in and around Okinawa.

Therefore “the plan to construct the Izumo was settled with its future conversion in mind to prepare for any possible contingency of the unavailability of the ASDF Naha Base,” according to one of the executives.

In those days, the U.S. F-35B stealth fighters, which could take off and land vertically, were in development, leading to a design conception of the Izumo on the premise that it could be converted to handle landings and takeoffs of the F-35B and other aircraft, such as the Osprey transport aircraft.

The approximately 250-meter long Izumo’s elevator connecting the deck with the hangar was designed to accommodate the F-35B fighter, which measures about 15 meters in length and about 11 meters in width.

Paint that can withstand the exhaust heat generated from F-35 fighter jets during landings and takeoffs was selected for the deck of the Izumo. It has also been expected to retrofit the Izumo with a sloping deck for takeoffs, the former MSDF executives said.

If the Izumo is converted to enable landings and takeoffs of the F-35B, the vessel can be utilized to refuel U.S. stealth fighter jets anywhere in the world at any time, including during military emergencies under the new national security legislation.

Even if it is designated a “defensive” aircraft carrier or with some other terminology, the refitted Izumo would be a vessel capable of attacking enemy targets.