Could China attack US? Why would US try to attack China in asia? Not an expert but that feels like losing proposition. I think people confuse proxy wars with wars. US is under no threat of being actually attacked.
old chinese proverb: Suffering is living, happiness is death(生于忧患,死于安乐)
You could ask the same question about Japan attacking America but they did do it.
If they think conflict is inevitable then they may well feel they will get an upper hand by moving first.