Actually, a Communist revolution in one of the smaller Western European nations in the 1910s would have not been implausible had ruling classes there been more intransigent about democratisation.
In Sweden, for instance, the Conservative Party was as hostile to universal suffrage as the conservative parties of Eastern Europe, but because with Sweden’s cool summers (and possibly consequent greater early industrialisation due in part to greater comparative disadvantage in agriculture) the landowning class had much less power than, say, in Germany. As a result, the big industrial businesses in northwestern Europe were forced to compromise with the working class’ demands, as shown by Göran Therborn in his 1977 The Rule of Capital and the Rise of Democracy.
In fact, Therborn and Dietrich Rüschemeyer along with Geoff Eley (Forging Democracy: The History of the Left in Europe, 1850-2000) and another book I read some time ago but cannot fish out, demonstrate that liberal democracy as it is presently known is as wholly proletarian as Marxism. So late as World War II, what are generally thought of as “democracies” almost always excluded racial minorities and before World War I only a few fishing- and forestry-based states allowed women to vote (and even these naturally more individuoegalitarian environments had given women the vote only within the previous quarter-century).
If a Communist revolution had taken place in one of the smaller European states, it would have definitively been overthrown if it had attempted to spread such a revolution in accordance with Marxist doctrine. However, if it had compromised with Marxist doctrine such states could simply have been ignored by the bigger powers.