 The aim was to achieve – without pursuing a quantitative parity with the US in terms of nuclear weapons and means of delivery – sufficient "guaranteed retaliation with an unacceptable level of damage to the enemy" in the event of a nuclear strike on the USSR via qualitatively superior nuclear power.The Tsar Bomba was not designed as a weapon, but as a proof-of-concept that larger warheads were practically possible and to exert psychological pressure on the United States.Research had also shown that the ammunition size of a thermonuclear weapon could be increased with minimal cost increases of 60 cents (in 1950s USD) per kiloton of TNT-equivalent explosive power.