During the ensuing peace, known as the Interim Peace by Finns, Oesch first returned to his previous post as the Chief of the General Staff for a few weeks, until taking the command of II Army Corps in April 1940.
Under den efterfølgende fred, som finnerne kalder Den midlertidige fred, vendte Oesch først tilbage til sin tidligere post som generalstabschef i nogle få uger indtil han overtog kommandoen over 2. finske korps i april 1940.