Complex sentence: Collectivization was thus regarded as the solution to the crisis in agricultural distribution (mainly in grain deliveries) that had developed since 1927 and was becoming more acute as the Soviet Union pressed ahead with its ambitious industrialization program.
Split into simpler sentences: Collectivization was thus regarded as the solution to the crisis of agricultural distribution (mainly in grain deliveries) that had developed since 1927. This problem became more acute as the Soviet Union pressed ahead with its ambitious industrialization program.