Japan insists the Izumo is a destroyer although it does have the ability to carry fixed-winged aircraft. Picture / AP
"Is this China's second aircraft carrier?" Foreign Policy magazine asked last week. The article ran a blurred picture, sourced from Chinese web forums, of a ship with a large flat top similar to a flight deck, above an open area that might be interpreted as a nascent hanger deck.
And was that a potential catapult? Beijing's sole existing carrier, the Liaoning, a revamped Soviet-era ship, lacks catapults, vital to launch "a much more advanced and capable air wing", including fighters and strike aircraft.
The Liaoning's ski-jump ramp limits its air wing to powerful planes able to get aloft using their own energy. The first successful landing, by a J-15 fighter jet, occurred in November. Catapults allow for more diverse and versatile aircraft. Foreign Policy speculates the new vessel's design may be based on an unfinished Soviet nuclear carrier, broken up in 1992.
But it is doubtful the Pentagon is worried. Yet. Compared to the US - which has 10 carriers, with two being built, plus decades of experience deploying carrier battle groups - the People's Liberation Army Navy (Plan) is a novice player.
"They're very much in the business of learning how to integrate an air wing on to a ship and to use them in a tactical way, as opposed to just landing and taking off," explains Rear Admiral Mike McDevitt [retired], a former carrier battle group commander and senior fellow at the Centre for Naval Analyses Strategic Studies. "China still has a long way to go."
No one is sure when the second carrier will be launched; McDevitt's guess is 2019-2020. Nor does anyone know much about its potential technological capacities.
"Will they be fighters, only good for defending themselves and an extension of China's [land] air defence? Or will they carry bombs as attack aircraft?" he asks. And will Beijing deploy carrier-based drones, a technical feat accomplished by the US Navy in July, giving the US a much greater surveillance and attack reach, useful in the vast Pacific.
But one thing is clear. China has joined the carrier club, which has less than a dozen members. Carriers will help Beijing project global power, the navy equivalent of hosting the Olympics. "If a big power wants to become a strong power, it has to develop aircraft carriers," wrote Senior Captain Li Jie, a Chinese Naval Research Institute researcher, last year.
Since 1945 US carrier battle groups have dominated the oceans. They appear immune from US budget cutbacks, although Defence Secretary Chuck Hagel has warned three carriers may be mothballed. By 2011, the New Yorker reports, military spending was more than $700 billion ($878 billion) a year, "more on defence than all the other nations of the world combined".
Nonetheless, the desire to retain carriers echoes US intentions in the "pivot" towards the Asia-Pacific region, deploying 60 per cent of naval resources - likely six carriers - in this theatre. Beijing smells containment.
Washington favours the Air-Sea Battle strategy - smashing enemies in a blitzkrieg-style assault - an option that, in part, needs carriers to launch attack aircraft. China sees itself as the target, raising the risk of Beijing trying to strike first, a possible reason for alleged PLA cyber attacks.
Meanwhile, carriers may provide added muscle in regional disputes. Take the tense sabre-rattling between Beijing and Tokyo over the Senkaku Islands in the East China Sea, one of several territorial disputes between China and its neighbours.
The Liaoning gives Beijing an edge, which may be increased by a second carrier. This addition "could significantly shake up the global power equation," says Foreign Policy.
Indeed, it may have sparked an arms race with Japan, which has implications for the US, Tokyo's major ally. This week Japan launched the Izumo, officially to deploy helicopters for anti-submarine warfare and surveillance.
While the Izumo, which Japan insists is a destroyer, despite its flight deck, does not have a catapult or a ski-jump, it has the potential to carry fixed-winged aircraft. China denounced Japan's "constant expansion of its military equipment".
"I'm sure Vietnam is watching China like a hawk," says McDevitt. "That's why they're building submarines." So are Singapore, Malaysia and Indonesia.
If the Izumo has regional implications, China's growing navy has made a bigger splash. Next year, China will make its debut at the US-hosted RIMPAC naval exercise, the world's biggest, albeit in less sensitive areas like disaster relief. It is recognition of the Plan's determination to defend China's fast growing global economic and political interests.
"Chinese strategists are worried about lines of communication," says Daniel Markey, senior fellow for India, Pakistan and South Asia at the Council on Foreign Relations. "They have the Malacca dilemma. So much of their shipping uses the Straits of Malacca."
The Chinese build-up also worries India, which has one carrier and is building two or three more. Markey says India fears encirclement via the "string of pearls", the spectre of Chinese navy facilities in Southeast Asia and East Africa, although both have fast-growing economic ties.
So is it inevitable a resurgent China will build a powerful carrier force?
The last time China projected formidable naval power was in the early 15th century, when the Great Fleet voyaged through Southeast Asia and the Indian Ocean. Thereafter, China turned inward. Last October Chinese academic Wang Jisi published Marching Westward. Jisi suggests Beijing counter the US pivot, which blocks Chinese eastward expansion, by swinging west into Central Asia, the Middle East and South Asia. It is a debate sure to be closely watched by US strategists.