Mussolini was well aware that the Allies had much stronger military force than Italy, and also they were occupying territories that he wanted to conquer. In order to be able to achieve his goals, Mussolini had to find a way in which the forces of his enemy will be weakened or out-forced. Germany was the ideal ally for this. The Germans had the strongest military individually, and also they shared a border after Austria was annexed. They had a common enemy, so it was in the interest of both sides to make an alliance and protect their backs, as well as fight together, and so they did and formed an alliance.
