If they were scared it would make more sense to not make waves with provocative statements. The whole thing of ammo requests from each other is part of their code of "chivalry", "honor", and "fair fights" to fellow white people, which would not be extended not to non-white people.
Based on their available data, sure I can see them being on the surface concerned, but then their habit of poking the dragon to me speaks of their inability to accept the data. At some level I think they doubt the data and think China's strength must be exaggerated and it must be a paper tiger that will collapse any day now, or that China will meekly take the slap, so that's why they are always shocked when there is retaliation. They've probably never had an Asian person punch back.