Before getting to the Chinese aircraft carrier issue, let me point out one very important thing missed by almost all commentators.
Osama Bin Laden triumphed, even though he was dead. His secondary goal, after helping to defeat the old Soviet Union, was to defeat the United States. He never expected to invade the U.S. and force everyone to wear beards and turbans. He used his followers' minimal resources to cause an economic and military collapse. The downgrading of U.S. debt (bonds) by Standard & Poor's was a public assessment of the success of Al Qaeda. Americans spent too much energy on global military dominance, too little energy on building a sustainable national economy. We lost, and everyone intelligent now knows we lost. We could still retrieve the situation by using our democratic system to take power away from the ruling corporate security state, but it looks like we are too stupid and lethargic to even do that. So, on to Chinese aircraft carriers.
The cry babies at the Pentagon, led byLeon Panetta, don't want the Chinese navy to have any aircraft carriers. In their minds Chinese aircraft carriers would shift the balance of power in the China Sea and require a buildup of the U.S. Navy in the Western Pacific. Which would require a bigger Navy budget.
The real question should be, given the history of China and aircraft carriers, why don't the Chinese already have a half dozen aircraft carriers? The answer is that China has not been a global military aggressor [Yes, I know, Tibetian nationalists and Vietnamese would disagree]. Of course, any country with a military is in some danger of becoming a military aggressor, but the Chinese Communist Party has a much better history of restraint than the United States Democratic Party does.
China, in the later 1800s and early 1920s, was being torn apart by the Great Powers. In 1914, During World War I, a Japanese proto-carrier, the Wakamiya, lowered 4 seaplanes in the sea, which then attacked German forces in Tsingtao (Qingdao), a German colony in China. No matter how you define the term "first aircraft carrier," by the 1920's these ships were being built by all the great powers, including the United States, Britain, Japan and France. By World War II naval battles were largely won or lost by aircraft launched from the carriers. The Barbaric U.S. attacks on Vietnam were also largely carrier-based.
The United States has been bullying nations with its aircraft carrier based terror bombing for closing in on a century now. Who are Barack Obama and Leon Panetta to tell the Chinese they can't have their own aircraft carriers for defense?
If Chinese aircraft carriers are not for defense, why should U.S. aircraft carriers classified as "defensive?" Aren't they inherently aggressive vessels, used only for war crimes? Including the current war crimes in Afghanistan?
If Panetta and the corporate security state he so proudly serves had half a brain left, they would negotiate a global treaty to decommission all aircraft carriers. Then China would not need to build new ones. Then the U.S. might have some money for schools or to invest capital to create jobs. Or to pay off those bonds that Standard & Poor's and others have suggested are less than sterling investments.
See also: history of the aircraft carrier