Indeed, it isn't like a game of Risk.
I think it's fair to say that if there's someone playing Risk with the world, it's not the US, at least in this part of the world:
That's the 'nine-dash' line, based primarily on China pulling that out of their ass and not a lot else. Essentially, it's China declaring the entire South China Sea theirs, why? Because
feck you, that's why.
That map speaks for itself on who islands like the Spratlys should belong to - or at the very least, who it shouldn't. But here's what they're doing on it, anyway - building missile bases.
What happens if you persist in your pathetic ignorance that the laws of the sea should somehow apply to you, despite China's obviously superior nine-dash claim to your waters?
Yeah - they ram and sink you. There's no video I can find, but they've done this even to Vietnamese coast-guard vessels, I believe.
I don't wanna get going on this because once I start on China I can't stop. I'll summarize it with this - I respect very, very much the anti-war, isolationistic sentiment now in vogue in the West. I sincerely believe it's rooted in noble, humanistic impulses; that it's purveyors mean well for both themselves and the world; and even that as a general rule it's probably the appropriate default position to take.
That all being said, I'd be cautious of one-size-fits-all mentality. Even from a purely anti-war perspective, I think it's clear that the odds of miscalculation are significantly worse in a situation where it's every man for himself against China;
@Ubik has rightly alluded to the prospect of a nuclearized East Asia. But more fundamentally, I don't think it's disproportionate, imperialist, or "neo-liberal" to recognize that historically, America has mutually-beneficial relationships with many friends in this region, who have legitimate interests in fearing a rampant Middle Kingdom reborn, who genuinely want and welcome American involvement in the area as a counterbalance.
Put it this way - is it better, even from a purely selfish consideration of the American national interest, to periodically steam the Seventh Fleet through the region, talk a good game on "historic friends and allies", show up at a few regional summits, and reap the trading and diplomatic advantages thereafter - or pick up the pieces of war afterwards?