>The Soviet Union collapsed because they persisted in promoting an unsustainable economic model, not because they feared the US.
True, but by itself it wasn’t enough to bring about the USSR’s fall. It was Reagan’s policies of confrontation which helped bring it about for example by Moscow’s arms buildup which increased the economic problems.
Reagan’s policies of confrontation had some impact, but not they did not constitute the major impact.
The Soviet Union had progressively weaker leaders from Stalin to Krushchev to Brezhnev (Brezhnev was famous for stagnation and decline). The KGB elite were the first to realise that the Soviet system was not working, so they attempted to tweak it around the edges (like the Chinese). They engineered the appointment of a reformer - Gorbachev. Unfortunately for them, Gorbachev promoted political freedom before economic freedom and the center collapsed.
China would have suffered the same fate as the Soviet Union had Deng (1)insisted on political freedom before economic freedom (2)blinked during Tienanmen square.
Bob Mugabe, Assad and the Burmese Generals have been running first grade oppressive regimes for decades on tight budgets. So, economic viability is not a prerequisite to running an oppressive regime.
As some one who has studied the collapse of the Soviet Union, I cannot praise Mikhail Gorbachev enough. I know it is not fashionable to praise Gorbachev in conservative circles, but think about this; what if the Soviet Union had Deng instead of Gorbachev, Reagan notwithstanding - we would be looking at a very different nation in Eurasia.
It requires immense personal courage to attempt to reform a fundamentally evil system from within and Gorbachev displayed tons of courage.
(Just FYI, Gorbachev reached out initially to Thatcher and Thatcher famously described him as “a man we can do business with”).
Reagan was great, but to conclude that the Soviet system collapsed simply because the Russians scared stiff of Reagan and US arms spending between 1981 and 1984, flies in the face of serious historical facts.