The Fairfax papers have splashed big this morning on the latest tranche of Snowden leaks released by Der Spiegel. Specifically, Fairfax reports that China has engaged in industrial-scale cyber-espionage in order to learn the secrets of Australia's next front-line fighter aircraft, the US-built F-35 Joint Strike Fighter.

I say 'news', but as the article notes, Chinese spying on the F-35 program has been known about for some years. What's interesting from the NSA Powerpoint slides released by Spiegel is the sheer scale of the operation (China gathered data 'equivalent [to] five Libraries of Congress') and the focus of China's efforts: radar design and engine technology. China is thought to be well behind Western technology in both those fields.

But there's one line in the NSA slides that the Fairfax report does not comment on, which is the reference to China spying on the air refueling schedules for US Pacific Command.

There are various reasons why this might interest China. One is that such schedules may give China clues about when it can expect to face American combat aircraft patrols or exercise in its region. Another is that it could influence how China operates its own aerial refueling fleet in future (its current aerial tanker capability is modest, at best). A third possibility is that China recognises the strategic value of America's tanker fleet, and sees it as a target in any future conflict.

Although aerial refueling is not the most glamorous aspect of air warfare, a Brookings Institution report from last October emphasises how central it is to America's ability to project power over long distances: 

...fuel logistics are a strategic criticality, effectively making the aerial refueling tanker force a strategic asset and potentially a strategic vulnerability.

China understands this vulnerability too. Beijing's adoption of an A2/AD strategy (anti-access/area-denial) is well documented. Simply defined, the strategy is designed to deter and delay US intervention in regional conflicts (for instance, over Taiwan or disputed territory in the South China Sea) by making it too dangerous for the US armed forces to operate around those areas. In particular, China has focused on building up its anti-ship capabilities, which would make it difficult for the US Navy to operate surface ships within range of any conflict.

The US would need to rely heavily on its stealthy combat aircraft to overcome such a strategy, but these aircraft need support from aerial refueling tankers if they are to have the range and staying power to really influence a conflict. That's especially true for the US Navy, which would have to operate its aircraft carriers from greater distances to avoid China's battery of anti-ship missiles.

But its also true of the refueling tankers themselves, which in years to come will face the threat of China's new stealth fighter, the J-20, a large fighter with the sort of range that will make it a direct threat to America's aerial fuel trucks. No wonder the Brookings study concludes that the US must 'plan for the defense of tanker aircraft in the same manner as other high value airborne assets.'

Photo by Flickr user US Air Force.