Airborne early warning and control
Airborne early warning and control flying radar aircraft as well as look down shoot down radar in fighter and interceptor aircraft allowed engaging low flying invaders again tipping the balance though this was partly ameliorated by succeeding generations of electronic countermeasures. Ultimately the US lead the way in first applying stealth technology to small strike aircraft like the F-117 and stealthy nuclear cruise missiles carried in conventional bombers for standoff release before the air defenses got too thick. The Soviet Union invested heavily in expensive to defeat intermediate and intercontinental range nuclear missiles and less on expensive to maintain patrol bombers, though they had to spend heavily on interceptors and surface to air missiles as well as radar sites to cover the huge landmass of the Soviet Union. The US joined with Canada to organize defense of the area of Alaska, Canada, and the continental United States with North American Aerospace Defense Command or NORAD using both interceptors, some armed with the nuclear AIR-2 Genie, and a surface to air missile component, which was at one point partly nuclearized. Development for the B-2 stealth bomber was intended for, and in anticipation of, a nuclear war and it was the first fully mature stealth aircraft to enter service. The F-22 Advanced Tactical Fighter was a stealth fighter and interceptor aircraft designed during the Cold War as a medium altitude air superiority fighter which was intended to destroy Warsaw Pact aircraft without ever being detected or engaged; both were introduced after the fall of the Soviet Union and the end of the Cold War.