In so much as generalizing a nation can still leave large exceptions, wars of conquest are useless to America: it hates running occupations, and it's own citizens are not going to move abroad in sufficient numbers to provide a labor force to utilize the conquests.
Moving against EU would not get them anything and the same bit as regarding China applies.
Truth is, war is an expense. You need to count on a serious long term benefit to wage it.
China’s per capita GDP is 1/7th that of the US.
To match the US GDP per capita would require China growing at 10%/yr for 35 years (while the US grows at 3-4% per year).
Thats 35 years of phenomenal growth, with no recessions, no “slow” years of only 5% growth (like the past 3 years). Assume an average of 7% growth (and US 3%) and now it takes 50 years to match the US per capita GDP.
This is why GDP growth of 5% is regarded as “bad” in China. They need double that.
And China needs to do this all the while having massive debt overhang, a world moving away from free trade (which their economy is highly dependent on) and a shrinking and rapidly aging population (by 2050 it will be 1 worker per retiree).
I don’t have a crystal ball, so who knows, but suffice to say if things stay relatively the same it’s going to be 2060-2070 before China is as rich as the US on a per capita basis.
Is it even possible in terms of resources? there are limits to growth and it may not be feasible for 1.5 billions people to consume and pollute as much as an average American.
Also are the US willing to lose their supremacy peacefully?