A war between Austria and Prussia would obviously afford the best opportunity, and his whole efforts were therefore directed to preventing a reconciliation between the two German Powers.

His great fear was that Austria should come to terms with Prussia, and surrender the Duchies on condition that Prussia should guarantee her Italian possessions.

When Bismarck visited Napoleon at Biarritz, the first question of the Emperor was, "Have you guaranteed Venetia to Austria ?" It was the fear of this which caused his anger at the Treaty of Gastein.

On the other hand, Bismarck had his reasons for anxiety.

It was always possible that Austria, instead of coming to terms with Prussia, might choose the other side; she might surrender Venetia in order to obtain French and Italian support in a German war.