The bomber was made obsolete in August 1957 when the Soviet R-7 Semyorka was first introduced.
Robert McNamara realized this in the early 1960’s which is why he decided to build 1,000 Minuteman silos and 41 SSBNs.
Wasn't your previous pseudonym U-238?
One major strategic advantage that the US has maintained over the Soviet/Russians is our bomber force. In times of crisis we can put planes in the air & loiter just outside their airspace. It’s the USAF equivalent of parking an aircraft carrier off your doorstep. Very intimidating.
Ballistic missiles, OTOH, are like submarines. They sit hidden and it’s difficult for the otherside to determine their actual alert status.