The Treaty of Brest-Litovsk is another good example of the tension between Marxist ideology and practical considerations which Lenin and the Sovnarkom had to deal with.
Lenin decided to sacrifice the international revolution in the interests of preserving the Bolshevik revolution in Russia.
The left SRs, who Lenin had allowed to the Sovnarkom in 1917, resigned in protest.
As a result of the discontent and opposition which the Treaty aroused in Russia, there was an assassination attempt on Lenin by a left SR which left him badly wounded in the neck.
The level of opposition to the treaty from across the political spectrum in Russia, including former Kadets and conservatives meant that a Civil War was now inevitable.