I will be interested to see how well the author has discussed the canal within a regional framework. Diana Wright, for example, published two posts presenting Australian and New Zealand accounts from April 1941 (here and here), which highlighting the Isthmus as a bridge for the Anzac retreat from Athens through the Peloponnese, and, then, later, a German prisoner of war camp. In the Eastern Korinthia Survey, we documented quite a few German gun emplacements and bunkers across the ridges and capes of the Corinthian Isthmus that give a sense of the German investments. The images below were taken at Akra Sophia not far from the canal.