Stalin decided not to be too obvious in his attack on Trotsky, leaving his partners Zinoniev and Kamenev to do the sliming. He maintained a normal, if not warm, relationship with Trotsky.
Trotsky was seen as a main contender, with Zinoniev and Kamenev being his rivals. Stalin seemed out of the picture at that time, and was not considered to be the most eminent of the three. He was also not seen as a contender for Lenin's position as he was not an ideologist, which a Communist leader had to be.
Trotsky reemphasised on his old theory of "permanent revolution", which was basically his stand that communism should spread beyond Russia and that a quick swift proletariat revolution should take place from the bourgeois to the socialist stage. He said that "October" had been the crucial stage in Party history, as it had been the time when Lenin accepted his theory of permanent revolution and held his revolution.
However, Trotsky's emphasis on October meant that he exposed another of his weak points. As Zinoniev pointed out, Trotsky had actually disagreed a number of times with Lenin's plan to begin the revolution prior to 1917. Stalin, on the other hand, appeared neutral and pointed out, seemingly without bias, that Trotsky was, after all, just a newcomer to Party ranks.
Stalin then proposed a plan of his own - Socialism in one Country. What this basically meant was that Russia should industrialise fully before embarking on a "Spread Communism to the World" policy. However, this theory was overshadowed by the struggle between Trotsky and the duo of Zinoniev and Kamenev.
In January 1925, the Central Committee removed Trotsky from the War Commissariat, even though he remained in possession of a seat in the Politburo. Although not totally crushed, Trotsky receded into the background. Any other man would have used the Red Army to defeat his opponents, but his loyalty to the party was paramount, and he accepted the decision without argument.
Trotsky may have been defeated, but Zinoniev and Kamenev soon realised they had not won the war. Stalin departed from the trio and joined his new allies Bukharin, Rykov and Tomsky, all three right-wing members championing Lenin's New Economic Policy. Stalin still remained in the background, preferring to be seen as a mediator more than a power-hungry individual. He claimed that collective leadership would be the only way to run the party.
Stalin's theory of "Socialism in One Country" was accepted in the Fourteenth Conference of the Party. Zinoniev and Kamenev paid little attention at first, but realised soon after that Stalin was their enemy now. Too late, they attacked the theory and severed all ties with him.
Rykov was named the chairman of the Council of People's Commissars. Tomsky was the leader of Soviet trade unions. Bukharin, originally the "Left" Communist of 1918 was now, like Rykov and Tomsky, allied with the right, and the leader of those who believed in Lenin's NEP being continued. Zinoniev and Kamenev opposed the continuation of the NEP, but had been thrust suddenly into the minority.
Zinoniev and Kamenev recognised that Stalin was the man they most had to fear. At the XIV Party Congress, they spoke sharply in criticism of Stalin. Sadly, their efforts completely miscarried. Zinoniev was punished by demotion from full member to candidate member of the Politburo. As reconstituted after the Congress, the Politburo had three new full members: Molotov, Voroshilov and Kalinin, all loyal henchmen of Stalin's. Stalin also added several supporters to the list of candidate members of the Politburo and the newly enlarged Central Committee.
Very little resistance was left after that, with only Zinoniev in Leningrad posing the main threat to Lenin's power. Stalin wrapped up his victory at the XVI Congress, sending in Sergei Kirov to take over from Zinoniev as Party leader in the city.
When the supporters of Trotsky, Kamenev and Zinoniev had scattered, the three made a common cause with each other. Just a few months earlier they had been bitterly attacking each other now they had united against Stalin, and to fight for their opposition to the continuance of the NEP and the "alliance with the middle peasantry" (Kulaks). The right wing, on the other hand, agreed that the NEP was needed but they knew it had to be dissolved in order to stay with communist views.
Stalin was not so concerned with policies and such as he was with getting rid of his former left-wing colleagues. On October 4 all the major opposition leaders replied with a statement admitting violation of Party statutes and pledging disbandment of the opposition, but they could not refrain from repeating their policy criticisms of the Politburo majority.
Trotsky was then removed from the Politburo and Zinoniev post as the president of the Comintern was removed from him. Trotsky submitted an article that called all people to change the government, which was basically a clear act of treason. Trotsky and Zinoniev were expelled from the Central Committee and, when they held street demonstrations, they were completely expelled from the party.
Stalin's actions should have, by right, united all his opposition. Instead, they were split up. Trotsky refused to accept the Congress decision and was exiled to Central Asia. Zinoniev and Kamenev submitted and renounced their earlier-stated views, and they were allowed to crawl back into the party.
As far as the Comintern was concerned, Trotsky had been defeated and Stalin had won. Followers of Trotsky left the party to build up parties of their own. This Stalin-Trotsky dispute shook the world and divided communist parties everywhere.
Stalin then turned his sights on defeating all other possible rivals he might have to his power. He turned on his allies Bukharin, Rykov and Tomsky, and by sheer political manoeuvring, employing the same skills as he had used before against Trotsky, Zinoniev and Kamenev, he got rid all his other rivals and established a fascist dictatorship in Russia.
Trotsky and his compatriots had given up all hope of stopping Stalin's ascendancy to power. They claimed that a bureaucracy had formed within the party and that it must be eliminated. However, they could not prove so, as Marx's theory was based on the Oriental way of life, and they shuddered at the thought of employing it against Stalin. And because of this they took the stand of the pre-war Social Democrats, opposing any and every government that took power except themselves. This stand naturally failed everywhere.
The Communists in the world had little chance to observe the personal differences and antagonisms between Stalin and Trotsky, and supported one or the other on the basis of his theoretical position. Here are the main ideological differences between the two.
Trotsky: It is impossible to build socialism in Russia. The peasants do not want it as collective farming and such are detrimental to their pockets. It is only possible to do so if the workers of the West, in America, revolted, as they would stand to gain more. He was right in this aspect.
Stalin: It is impossible to wait for the workers of the West to revolt. They will never do so in the near future and their government has too strong a hold over them. Socialism must be built in Russia and only by using the peasantry can it be achieved. He was right too.
However, in the end, Trotsky could not ascertain that the Western workers were Communist, only claiming that they would be soon. Stalin could not admit that the Russian peasants were Communist either, but he sure could compel them to be. As a result, Trotsky retreated into utopianism, while Stalin proceeded to establish a minority dictatorship built on terror. To an extent it could be agreed that Stalin forced Trotsky out of the party by turning other members away from his political views.