What Were the Reasons/causes for the Great Terror?

Q1 What were the reasons/causes for the Great Terror; How far was Stalin responsible for the Great Terror; Was the Terror Stalin's personal decision?

In 1918, the Bolshevik party, through means of insurrection, seized control of the government in Russia. Promising to bring an end to repression and tyranny by the rich, the new Soviet government quickly transformed itself into a very repressive regime. There occurred a most vicious and peculiar period of violence at the end of the 1930's that has been remembered as the "Great Terror". It is interesting to note is that during this time the Bolsheviks launched their campaign against members of their own party. Indeed, those caught up in this nightmare thought that Stalin's only perceivable motive was to destroy the best people in the party. There have been many theories concerning the cause of the Great Terror over the years. Modern scholarship suggests that instead of just one cause it was, in fact, the combination of several factors, including the political situation in the 1930's, Stalin's personality and psychological state, and the economic advantages of The Terror that all conspired together to form the unfortunate events that took place.

The political events that eventually led to the Great Terror began in February of 1934 at the Seventeenth Party Congress. Dissatisfaction began to emerge against Stalin and he saw evidence for the first time that his position as leader was threatened. Events at this congress are dim, but there are accounts that a group of conspirators actually met and discussed removing Stalin from his post and replacing him with Kirov. Kirov was consulted, but he chose instead to warn Stalin of the threat. Additional cause for concern occurred at the congress when the vote for the Central Committee was taken by secret ballot and Stalin did badly. Some memoirs claim that Kaganovich, who was responsible for counting the votes, had to actually "cook the books" to ensure Stalin's reelection.

Stalin was clearly threatened politically. It served to inflame the already deep-seated paranoia with which Stalin viewed the world and those around him. Kirov quickly fell victim to this distrust, for although he had approached Stalin on his own initiative at the Seventeenth Party Congress, he was one of the most popular candidates to take over if Stalin was removed. This "threat" inevitably led to the estrangement between Stalin and Kirov that continued up to Kirov's assassination.

On December 1, 1934 Leonid Nikolaev assassinated Kirov inside the Smolny Institute. Speculation still remains as to whether Leonid acted alone towards Kirov or whether Stalin's had directed the assassin. Regardless of the cause, Kirov's death officially began the terror and bloody purges that would engulf the party and ultimately lead to the imprisonment or death of many party leaders, as well as normal members.

While Stalin played the mourner-in-chief at Kirov's funeral he moved within the party to use Kirov's death to justify the building of the procedural mechanisms he would later use in the Great Terror. The bloodshed began just five days after the assassin's bullet struck down Kirov when twenty-six people were executed. The political situation at the time was obviously one where Stalin had reason to be concerned.

Stalin was a paranoid individual. Stalin was a very lonely and isolated individual at this time. The suicide of his wife, Nadya, coupled with the opposition of other party members left Stalin surrounded by subordinates with almost no true friends. Surrounded by real threats and suspicious of everyone he began to lash out violently at anything