Even rivers and streams could quickly become enlarged and themselves be extreme obstacles for military forces. All of this coupled with the disease and the impact the horrible conditions could have on the morale of invading armies made the rasputitsa weather feared by most high commands and operational leaders.
Rasputitsa conditions aiding in military efforts are most famous in the Russian defense against Napoleon and of course against the Wehrmacht. Here, the relatively unaware foreign troops encountered great difficulties as most of their equipment was simply not designed to be used in such an environment. For example, the Wehrmacht's tanks and trucks quickly became bogged down and the notable designs such as wide tracks that were implemented in Soviet vehicles were just not known to the Germans.
Furthermore, the initial refusal of Hitler to admit that the war was most likely going to continue into fall and winter meant that even minor preparations were either too late or not met at all.