Why does the US keep cussing about china?

i mean the US owes china billions or even trillions if i'm not mistaken. they keepcomparing china's military with theirs especially since china now has an aircraft carrier. the US compares everything from the the size of the military to the strength of their jets to china's economy blah blah blah. is the US just insecure or what? i have nothing against america i'm just wondering why. no hate comments please.