Complex sentence: Hampered by lack of fuel as well as several serious defeats, the Italian Navy spent most of the war confined to port as a result the Mediterranean Sea was not in any real sense Italy's "Mare Nostrum".
Split into simpler sentences: Hampered by lack of fuel as well as several serious defeats, the Italian Navy spent most of the war confined to port. As a result the Mediterranean Sea was not in any real sense Italy's "Mare Nostrum".