Many countries have been badly bombed. Please ask a more specific question.
The reason why Japan bombed us was because we cut off our metal shipment to them in fear of them attacking other countries
US
3
London was bombed along with many other cities because it was a link to other countries through trade
They won and collapsed the means for Japan to make war.
No states in the USA have been bombed in a long time.
Iran Iraq afganisan
We bombed them back
nagasaki and hiroshima
they bombed us
North Korea has threatened to bomb lots of countries but hasn't bombed any countries yet (although it did invade South Korea during the years 1950-1953).