When the superpowers came close to nuclear conflict during both the Cuban Missile Crisis and the Able Archer/VRYAN Crisis, they developed the view of mutual assured destruction. Andropov was followed as Soviet leader by Konstantin Chernenko, who in turn was followed by Mikhail Gorbachev, and Gorbachev brought a far less hostile, ideological, and reflexively skeptical approach to the relations between the superpowers, helping to build an atmosphere of trust between the two. Reagan's views regarding nuclear weapons and ICBMs following this crisis changed, discarding his preconceived notions of general Soviet bad faith, leading him to come full circle and famously declare that "Nuclear war cannot be won and must not be fought". These new attitudes on both sides nearly brought about the disarmament and destruction of ICBMs, long-range SLBMs, and, possibly even nuclear weapons themselves at a groundbreaking disarmament summit between Gorbachev and Reagan at Reykjavík in 1986. The sticking point causing agreement to be unreachable was the SDI Program, and missile defense continues to be an issue for the Russians today. However, the INF Treaty, the Conventional Forces in Europe Treaty, and the START Treaty could be said to be the result of the change in leaders and leaders' attitudes that the Able Archer/VRYAN crisis facilitated, just as the Non-Proliferation Treaty and the Partial Test Ban Treaty, as well as U.S.-Soviet détente, were the result of the Cuban Missile Crisis.