Ummm....WWII bombings of Japan and Germany. Pretty standard practice hitting civilian targets.
Mind you...our tech has allowed us to get away from that practice so I'm not sure that's the most telling point, but it's there in our history.
China would LOVE to see us go into Iran. I'm sure they see it as the USA's potential Ukraine invasion with us playing the part of Russia. China can then support Iran with arms shipments.
How that works out I don't know.