Most dastardly double cross of all time?

When the Soviet Union collapsed in 1991, Uncle Sam dealt Russia a deal. If they would disband the Warsaw Pact (Eastern European neighbors aligned with USSR), the West would disband NATO. Russia agreed and complied. Uncle Sam didn't, double crossing Russia and gobbling former Warsaw Pact nations into NATO right up to Russia's doorstep. In 2014, the West instigated a coup against the pro-Russian, but duly elected Ukraine president in an effort to not only bring Ukraine into NATO, but destabilize Russian president Putin. Naturally and justifiably, Russia pushed back, grabbing back the Ukraine province of Crimea containing a strategic Russian naval base. US war hawks promptly restarted a slightly cooler version of the Cold War, demonizing Russia and its president Putin as the bad guy in this totally avoidable crisis.

Presumptive GOP candidate Donald Trump is the most hate-filled, boorish, uninformed and dangerous main party candidate in history. But even his shotgun approach of reckless and incoherent spewings occasionally hits the mark. His criticism of NATO and cuddling with Vladimir are more on the mark (even though he's clueless why) than the mainstream ravings of the political establishment promoting new Cold War with Russia and pushing the Nuclear Clock closer to Midnight.