After the disastrous Battle of Caporetto in 1917, Italian forces were forced far back into Italian territory as far as the Piave river. The humiliation led to the appointment of Vittorio Emanuele Orlando as Prime Minister, who managed to solve some of Italy's wartime problems. Orlando abandoned the previous isolationist approach to the war and increased coordination with the Allies. The convoy system was introduced to fend off submarine attacks, and allowed Italy to end food shortages from February 1918 onward. Also Italy received more raw materials from the Allies. The new Italian chief of staff, Armando Diaz, ordered the Army to defend the Monte Grappa summit, where fortified defenses were constructed; despite numerically inferior, the Italians managed to repel the Austro-Hungarian and German Army. The year 1918 also saw the beginning of official suppression of enemy aliens. The Italian socialists were increasingly suppressed by the Italian government.