Western betrayal or Yalta betrayal are popular terms in many Central European countries, especially in Poland and the Czech Republic but also in non-Western nations which refers to the foreign policy of several Western countries which violated allied pacts and agreements during the period from the Treaty of Versailles in 1919 through World War II and to the Cold War, as rooted in hypocrisy and betrayal.

About the Western betrayal concept:

Quotes

* and so in the evening released from facts I can think

about distant ancient matters for example our

friends beyond the sea I know they sincerely sympathize

they send us flour lard sacks of comfort and good advice

they don't even know their fathers betrayed us

our former allies at the time of the second Apocalypse

their sons are blameless they deserve our gratitude therefore we are grateful

they have not experienced a siege as long as eternity

those struck by misfortune are always alone

the defenders of the Dalai Lama the Kurds the Afghan mountaineers

-- from Zbigniew Herbert's poem Report from the Besieged City

• It is said that by doing that [i.e abandoning Eastern Europe] they secured the imminent participation of Stalin in war against Japan. Already armed with the Atomic bomb, they did pay for Stalin so that he wouldn’t refuse to occupy Mandzhuria, to help Mao Zedong to gain power in China and Kim Ir Sen in half of Korea!… Oh, misery of political calculation! When later Mikolajczyk was expelled, when the end of Benesh and Masaryk came, Berlin was blocked, Budapest was in flames and turned silent, when ruins fumed in Korea and when the conservatives fleed from Suez – didn’t really some of those who had better memory recall for instance the case of giving away the cossacks?

Alexander Solzhenitsyn, Gulag Archipelago, Part I, ch 6 (‘That Spring’)