A) Trotsky's contribution to the success of the Bolsheviks up to 1922 was vital, as he was a key figure during the November Revolution. He persuaded Lenin to wait until the time was right for the take-over of Petrograd. This was important as it secured the control over the city. Trotsky also organized the take over of the city, seizing the important points of communication and control over bridges, telegraph offices and the railway station. This resulted as a success for the Bolsheviks, due to Kerensky fleeing the city allowing the Bolsheviks a comparatively straight forward take over of the Winter palace, where the Provisional Government was. This secured the Communist victory.
Trotsky also played a major part in organizing the Civil War, which secured the Communists victory against the Whites, and secured the Communists position in Russia. He was the Commissar for war, thus he built up the Red Army from nothing, introducing conscription for over eighteen years of age. He brought in nearly 50,00 experienced former Tsarist officers and appointed political commissars. Together they seized many of the key places, such as the central area Western Russia, which contained most of the large Industrial centers able to produce munitions and war supplies. They also had control of the railway lines, which connected Moscow to the rest of the country. This meant that they could send soldiers and munitions quickly to any place in the battle.
Trotsky took a practical approach in organizing the Red army; he recognized that the morale and loyalty of the army was as essential as its skills and size. Harsh disciplines were used to make sure the troops stayed loyal. Above all, Trotsky's fairness made the Red army different from the imperial army; Trotsky used both means of control over his troops, implying harsh disciplines whilst being liberal with them. Therefore, Trotsky was loved and respected by his troops, and together they saved the revolution, as the Whites were defeated.