and the f-117. stealth is just the latest technology that permits the existence of unescorted bombing. when the cold war kicked off both the us and russia were looking at the prospect of having to attack each other from ranges far in excess of what escort fighters could muster so it was simply natural to start designing bombers that could beat interception by themselves. it went from flying ever faster and higher until the guided missile put an end to that, then it went to sneaking in low under terrain shadow to beat the sensor, before today's low observability meta (still just trying to beat the sensor). but the core conceit is still just to be able to put bombs on target while beating any interception attempt. i think the future will probably see things come back around full circle, with better sensors and miniaturization shifting the meta back to beating the interceptor again, this time with point defense weaponry. flying fortress but 2050...