Anyway, let's say that the victorious Central Powers are able to maintain the Brest-Litovsk settlement until the 1940s or so, at which point a newly industrialized Russia, whether Communist or White-led/Fascist, decides to spark a revanchist war:Deep operation (Russian: Глубокая операция, glubokaya operatsiya), also known as Soviet Deep Battle, was a military theory developed by the Soviet Union for its armed forces during the 1920s and 1930s. It was a tenet that emphasized destroying, suppressing or disorganizing enemy forces not only at the line of contact but also throughout the depth of the battlefield.
The term comes from Vladimir Triandafillov, an influential military writer, who worked with others to create a military strategy with its own specialized operational art and tactics. The concept of deep operations was a national strategy, tailored to the economic, cultural and geopolitical position of the Soviet Union. In the aftermath of several failures or defeats in the Russo-Japanese War, First World War and Polish–Soviet War, the Soviet High Command (Stavka) focused on developing new methods for the conduct of war. This new approach considered military strategy and tactics, but also introduced a new intermediate level of military art: operations. The Soviet Union was the first country to officially distinguish the third level of military thinking which occupied the position between strategy and tactics.
Using these templates, the Soviets developed the concept of deep battle, and by 1936, it had become part of the Red Army Field Regulations. Deep operations had two phases: the tactical deep battle, followed by the exploitation of tactical success, known as the conduct of deep battle operations. Deep battle envisaged the breaking of the enemy's forward defenses, or tactical zones, through combined arms assaults, which would be followed up by fresh uncommitted mobile operational reserves sent to exploit the strategic depth of an enemy front. The goal of a deep operation was to inflict a decisive strategic defeat on the enemy's logistical abilities and render the defence of their front more difficult, impossible—or, indeed, irrelevant. Unlike most other doctrines, deep battle stressed combined arms cooperation at all levels: strategic, operational, and tactical.
Anyway, what would Russia's odds of success in such a 1940s revanchist war have been and would the British and/or the Americans actually be willing to provide a lot of Lend-Lease-style aid to Russia in this scenario in the hope that Russia will give Germany a bloody nose? I would presume that the Brits and/or the Americans would still be angry at Germany for their World War I loss, after all--albeit not actually up to the point of them being willing to send their own troops to help Russia fight Germany in a 1940s revanchist war.
The reason that I became so interested in this question is because the Soviet Union was still able to inflict decisive victories on the Germans and to fight effectively against them even when its World War II military situation was even worse than the situation that the Communists faced at the time of the Brest-Litovsk peace treaty--other than in the Caucasus, of course:
If the Soviet Union could lose so much territory, people, industries, and natural resources to the Nazis (even if they managed to evacuate some of it/them beforehand) and still continue fighting effectively against the Nazis with a lot of Lend-Lease aid, I'm wondering if the same could have also been true for Russia in a 1940s revanchist war against Germany in a scenario where the Central Powers won World War I, especially very late in the war.