Initiative could never be made to be trustworthy and that such a system would inevitably be unreliable and constitute a menace to humanity in its own right. Parnas said he joined the panel with the desire to make nuclear weapons "impotent and obsolete" but soon concluded that the concept was "a fraud". Treaty obligations Another criticism of SDI was that it would require the United States to modify previously ratified treaties. The Outer Space Treaty of 1967, which requires "States Parties to the Treaty undertake not to place in orbit around the Earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction, install such weapons on celestial bodies, or station such weapons in outer space in any other manner" and would forbid the US from pre-positioning in Earth orbit any devices powered by nuclear weapons and any devices capable of "mass destruction". Only the space stationed nuclear pumped X-ray laser concept would have violated this treaty, since other SDI systems, did not require the pre-positioning of nuclear explosives in space. The Anti-Ballistic Missile Treaty and its subsequent protocol, which limited missile defenses to one location per country at 100 missiles each (which the USSR had and the US did not), would have been violated by SDI ground-based interceptors. The Nuclear Non-Proliferation Treaty requires "Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control." Many viewed favoring deployment of ABM systems as an escalation rather than cessation of the nuclear arms race, and therefore a violation of this clause. On the other hand, many others did not view SDI as an escalation. SDI and MAD SDI was criticized for potentially disrupting the strategic stability afforded by the doctrine of mutual assured destruction. MAD postulated that intentional nuclear attack was inhibited by the certainty of ensuing mutual destruction. Even if a nuclear first strike destroyed many of the opponent's weapons, sufficient nuclear missiles would survive to render a devastating counter-strike against the attacker. The criticism was that SDI could have potentially allowed an attacker to survive the lighter counter-strike, thus encouraging a first strike by the side having SDI. Another destabilizing scenario was countries being tempted to strike first