Operation Eclipse was a dossier about the plans for the German territory after the war. He included the new boundaries of Germany and the division of German territory among the Allies, as was appointed in the Yalta Meeting.
A copy of the plan from a British Headquarters fallen in German hands, and was classified as State Top Secret by Hitler. "His military advisers and their staffs could study the plan, but no on else. Not even the members of his own cabinet were informed".
The possibility of see the plan, despite being not a "strategic document - that is, it did not warn of imminent enemy moves that called for corresponding German countermoves", the plan helped to answer several questions that were in the mind of OKW for years. The first one: How srong was the alliance between the Western Powers and the Soviet Union?
It was known by the Germans the differences about Great Britain and Russia, the alliance between them was imposed by the need, before all. So, the big bet for the Germans was wait for the corrosion of the Alliance between the Allies given the different ideologies. This was the basic idea of the Ardennes offensive.
But the copy of Eclipse revealed that the plans were already made, the document was dated November 1944, defined as "planning and operations for the occupation of Germany".
"The Allied intent promised no hope, no future for Germany. It was clear that even if the Reich wished to capitulate, there was no way she could do so short of unconditional surrender. To Jodl, this meant that there was nothing left for Germany, but to fight to the end."
Heinrici, now formal commander of Army Group Vistula, after read carefully the plan, said: "Das ist ein Todesurteil - This is a death sentence".
Source: C. R. The last battle. 1966.
A reproduction of the Operation Eclipse can be found here.