When Navy Secretary Carlos Del Toro returned from his trip to Japan, he fired off a tweet that touted his tour of that country's "Aircraft Carrier Izumo." It was a short comment that recognized an important new naval reality for the longtime ally.
Japan's pacifist constitution meant its naval forces have relied on ships carrying helicopters for self-defense, not fighter jets -- and it avoided using the term aircraft carrier -- since the end of World War II.
Del Toro, whether intentionally or not, gave a public U.S. acknowledgment of a historic shift by Tokyo toward its past as a carrier power. Late in 2018, the Japanese announced plans to refit two helicopter carriers including the Izumo for U.S.-built F-35B Lightning II fighters, part of an increasingly urgent effort to counter growing Chinese sea power.
A Navy spokesman said, "The tweet does not signal a change in how the U.S. officially recognizes the ship."
Japan has a self-defense force, what most outsiders would recognize as a military, but its constitution proclaims that "land, sea, and air forces, as well as other war potential, will never be maintained," meaning that it has historically avoided any military action or buildup considered offensive.
"Governments have argued that Japan has the right to maintain capabilities and use the 'minimum necessary level of self-defense,'" explained Jeffrey Hornung, a scholar on Japan at Rand Corp. "Historically, anything that exceeds that is considered war potential, and therefore it violates the Constitution."
Traditionally, there were four things that undisputedly fell into that category, Hornung explained: intercontinental and intermediate-range ballistic missiles, long-range bombers, and aircraft carriers.
However, in recent years, Tokyo has increasingly debated more robust military capabilities, such as the fixed-wing aircraft carriers, as fears over the rise of China grow.
The Izumo is a helicopter destroyer that at 27,000 tons fully-loaded is larger than Italy's aircraft carrier, the Garibaldi.
The ship is small compared to the U.S. Navy's 90,000-ton Nimitz-class carriers or even China's 58,000-ton Liaoning carrier. But it is the largest Japan has put to sea since World War II.
Hornung said China's growing power in the region and its recent moves around the disputed Senkaku Islands are a major factor in the drive to refit the Izumo and her sister ship, the Kaga, to effectively function as small aircraft carriers.
"They want to be able to have that capability [to launch planes] at sea, because there's an expectation that the runways will be destroyed within the first launch," Hornung said.
The move gives another platform for a U.S. ally to fly the most advanced fighter jet in the world.
On Oct. 3, a pair of Marine Corps F-35B stealth fighter jets successfully did a takeoff and landing off the Izumo's deck. The Marine Corps released a statement announcing the accomplishment, and the Japanese Maritime Self-Defense Force publicly released a video.
This exercise was the first time fighters had flown from a Japanese carrier since World War II.
The decision to refit the Izumo prompted Chinese state-run media to attack Japan's wartime past.
"Japan must not forget its infamous history of invading countries and regions in the Asia-Pacific region during the WWII, as making an aggressive move like this may drive the country to repeat its militaristic history," a 2018 Global Times article said.
-- Konstantin Toropin can be reached at email@example.com. Follow him on Twitter @ktoropin.