The outcome of the Balkan Wars sparked a very strong revanchist sentiment among Bulgarians. In 1915 Germany promised to restore the boundaries according to the Treaty of San Stefano and Bulgaria, which had the largest army in the Balkans, declared war on Serbia in October the same year. In the First World War Bulgaria decisively asserted its military capabilities. The Second Battle of Doiran, with general Vladimir Vazov as commander, inflicted a heavy blow on the numerically superior British Army, which suffered 12,000 casualties against two thousand from the opposite side. One year later, during the Third Battle of Doiran, the United Kingdom, supported by Greece, once again suffered a humiliating defeat, losing 3,155 men against just about five hundred for the Bulgarian side. The reputation of the French Army also suffered badly. The Battle of the Red Wall was marked with the total defeat of the French forces, with 5,700 out of six thousand men killed. The 261 Frenchmen who survived were captured by Bulgarian soldiers. Out of a 4.5 million population, Bulgaria fielded 1,200,000 people in its army. Even this vast expansion of the military could not save Bulgaria from the imminent defeat of its patron Germany. The Allied breakthrough at Dobro Pole and the subsequent soldier mutiny at Vladaya completely disrupted the war effort in 1918. Bulgaria capitulated soon after these events. Bulgarian casualties amounted to 412,000, along with 253,000 refugees created from the lost territories.