(2) Difference: Different purposes. The former should defend the nascent Soviet regime, while the latter should realize the transition to socialism; The means are different. The former focuses on military and political means, while the latter focuses on economic means.

Reason: It is suitable for Russia's national conditions and productivity level at that time.

(3) The socialist model cannot remain unchanged. Socialist construction must proceed from the national conditions, keep pace with the times, and carry out continuous reforms according to the level of productive forces.

This topic investigates the background, characteristics and far-reaching significance of the implementation of the new economic policy. The answer to the question (1) is "direct cause"; To answer the question (2), we should compare it with the wartime policy from many angles; Question (3) is open-ended. Combined with the practice of socialist construction in China, we can answer the enlightenment and make sense.