Paul von Kleist was interviewed by Basil Liddell Hart

http://www.spartacus.schoolnet.co.uk/GERkliest.htm

We did not underrate the Red Army, as is commonly imagined. The last German military attaché in Moscow, General Kostring - a very able man-had kept us well informed about the state of the Russian Army. But Hitler refused to credit his information.

Hopes of victory were largely built on the prospect that the invasion would produce a political upheaval in Russia. Most of us generals realized beforehand that if the Russians chose to fall back there was very little chance of achieving a final victory without the help of such an upheaval. Too high hopes were built on the belief that Stalin would be overthrown by his own people if he suffered heavy defeats. The belief was fostered by the Führer's political advisers, and we, as soldiers, didn't know enough about the political side to dispute it. There were no preparations for a prolonged struggle. Everything was based on the idea of a decisive result before the autumn.

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