"However, in a nation where ordinary folk only get to hear one side of every story, both arguments are unfortunately likely to be accepted without question."
No, the people are likely to 'accept' that the government organ says this, and then wonder what the real story is. They won't 'accept' this as the simple truth. They are not that 'simple'.
As to the above respondents who mouth platitudes about PRC merely building up their forces proportionately... Ask Vietnam, Phillipines, Brunei, Malaysia, Taiwan, Japan, Korea or anyone else in waters anywhere near China. Ask if they 'like' the Chinese military showing up claiming the entire South China sea as China's. Fishing, oil... all China's. Look up the Spratlys - claimed in part by four countries - and entirely by China.
'Communist' PRC is using maps from the imperial eras, and enforcing them. This is dangerous, now and every time. Anyone up for lebensraum games?
Reuters: Insight: Conflict looms in South China Sea oil rush
Look at the second map here: Territorial disputes in the South China Sea