Complex sentence: On the basis of the operational units of the Silesian Military District in case of war was to be formed Second Army, which was included in the Polish Front part of the United Armed Forces of the Warsaw Pact.
Split into simpler sentences: On the basis of the operational units of the Silesian Military District, the Second Army was formed in the event that war broke out, and the army was included in the Polish Front. This was in accordance of the United Armed Forces of the Warsaw Pact.