A decisive factor in the Russian Revolution, especially the Boleshevik one in November was soldiers being sick of the war and deserting/mutinying.
However, from 1918 to 1921, the Bolesheviks controlled an Army to fight and win its war against Civil War opponents and foreign interventionists.
How were the Bolesheviks able to keep control of their troops where prior regimes could not?
While theoretically, all the reasons listed below (and others) could account for it, I'm interested in what you think the *most* important reason is.
Could any other ideological/political alternative to the Bolsheviks in Russia from 1917 to 1921 have maintained a similarly obedient and effective a force as OTL's Red Army?