DBWI Czechoslovakia didn't ally with USSR

As we all know, in 1938, Czechoslovakia decided to reject the Munich Agreement and ally with the USSR to fight Germany, and USSR declared war with Poland as Poland rejected to allow Soviet army go across its border to send its army to Czechoslovakia. This ends up with USSR get its border extend to Curzon Line B (as England and France declared they will protect Poland if USSR army go across that line) and Czechoslovakia turn communism and get Silesia, most part of Germany become a USSR puppet, as England and France not involved at all.

What would happen if Czechoslovakia didn't ally with USSR? This is likely to happen as USSR can't send its army without an agreement or a fight with Poland or Romania. Will Czechoslovakia just surrender or fight on their own?
Will the war be prevented? Or it will still begin later?
 
It gets eaten alive. Germany, France, and the UK eventually form an alliance, and will inevitably clash with the USSR. Conflict might go either way, but I think in the end the Iron Curtain will be at the Pyrenees rather than at the Rhine. Might get overextended, though, and not last as long as it has lasted IOTL.
 
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