Upon entering the war, geography was also a difficulty for Italy as its border with Austria-Hungary was along mountainous terrain. In May 1915, Italian forces at 400,000 men along the border outnumbered the Austrian and Germans almost precisely four to one. However, the Austrian defenses were strong even though they were undermanned and managed to hold off the Italian offensive. The battles with the Austro-Hungarian Army along the Alpine foothills in the trench warfare there were drawn-out, long engagements with little progress. Italian officers were poorly trained in contrast to the Austro-Hungarian and German armies, Italian artillery was inferior to the Austrian machine guns and the Italian forces had dangerously low supply of ammunition; this shortage would continually hamper attempts to make advances into Austrian territory. This combined with the constant replacement of officers by Cadorna resulted in few officers gaining the experience necessary to lead military missions. In the first year of the war, poor conditions on the battlefield led to outbreaks of cholera causing a significant number of Italian soldiers to die. Despite these serious problems, Cadorna refused to back down on the strategy of offense. Naval battles occurred between the Italian Royal Navy ("Regia Marina") and the Austro-Hungarian Navy. Italy's warships were outclassed by the Austro-Hungarian fleet and the situation was made more dire for Italy in that both the French Navy and the (British) Royal Navy were not sent into the Adriatic Sea. Their respective governments viewed the Adriatic Sea as "far too dangerous to operate in due the concentration of the Austro-Hungarian fleet there".