The Brusilov Offensive began with a massive and accurate artillery bombardment that was brief, unlike the past shelling that could last quite a long time as it surprised Austro-Hungarian forces in Galicia. They had been unable to evacuate their forward trenches and place their reserves in a position where the trenches could be reinforced in the face of a determined Russian offensive. Russian shock troops launched attacks against what were perceived to be weak points in their enemy's lines in order to allow for the bulk of advancing Russian forces to achieve breakthroughs all along the line, proving to be successful. In Ukraine, the city of Lutsk was successfully captured alongside Archduke Jozef Ferdinand who was replaced by General Tersztyanskzy while Evert's forces launched their attack against German forces and tied them down before they could be shifted to reinforce the retreating Austro-Hungarian troops. General Evert was successful in the Battle of Brest-Litovsk but was hesitant in continuing his part of the Brusilov Offensive in order to take Warsaw and potentially rally the Poles under Russian command, opting to simply consolidate over the territory he had taken. Brusilov seized Lemberg, Komorov, Rava Russka, Czernowitz and Kolomeo in a series of his overwhelmingly successful offensives as he fortified the towns formerly under the occupation of the Central Powers. Meanwhile, troops coming from the Caucasian Front continued to reinforce the Eastern Front with much needed manpower and firepower that had been used in defeating the Ottoman Empire while the successful Yudenich and Brusilov Offensives boosted Russian morale. Russian nationalism had undergone a bit of a revival with the defeat of the Turks and occupation of the holy city of Constantinople where Tsar Nicholas II was photographed shaking hands with Emperor Haile Selassie, both of them surrounded by important figures from their respective countries. However, the Brusilov Offensive's successes had led to an increased revival of Russian nationalism throughout their Empire as Brusilov became increasingly popular amongst the average Russian. It had come dangerously close to breaking the back of the Austro-Hungarian Empire, rendering it effectively impotent in being able to conduct any offensive action and was just barely holding the line against the Entente. It bolstered the Romanian entry into the Entente, serving only to demoralize the Central Powers and bolster the position of the Entente who saw that their chances of victory were coming even closer to reality.
On the Western Front, a reconnaissance patrol, consisting of experienced British troops from the former Mesopotamian Front, had found a gap in the German lines and reported this to British High Command who sent a combined Anglo-Dominion force to exploit it. This caught the Germans off-guard who were unable to defend against the ruthless advance of British forces that managed to capture the third line of the German defenses as Entente defensive lines established themselves at Gommecourt and Peronne. Falkenhayn ordered that German attempts at capturing Verdun be halted in order to provide reinforcements in the face of the British Somme Offensive before being replaced by Paul von Hindenburg for his failure to defend. Meanwhile, Anglo-French forces launched an attack against German forces at Gommecourt in their attempts to take the city and were successful in doing so, albeit with heavy casualties as a result of the stiff German resistance. The Germans would manage to retake Le Transloy but failed to keep Puisieux in the face of overwhelming numerical superiority and a new British weapon that had been referred to as a "tank", a behemoth of an armored vehicle that rolled over German defenses and horrified German soldiers. Despite these losses, the Germans had been able to reinforce the Hindenburg Line and force the Entente to consolidate over their new lines as winter began to set in on the Western Front. The World War seemed to have turned in the favor of the Entente with the capitulation of the Ottoman Empire and near-collapse of Austria-Hungary at the hands of Russia as Romania joined. As this all occurred, Ethiopian troops from Mesopotamia and Anatolia began to reinforce the exhausted Ethiopian Expeditionary Force which had been recently receiving heavy casualties in the face of determined German offensives and counter-offensives to retake their forward trenches. The Ethiopian Expeditionary Force to France now swelled to 100,000 men strong as the large pool of manpower and industrial resources could now be brought to bear against the Germans on the Western Front.
However, there was one thing that sealed the fates of the German and Austro-Hungarian Empires - the Zimmerman Letter, a German telegram that was to be sent to Mexico City which promised the Mexicans their former territories that had been annexed by the USA if she would join the World War. Not to mention, the Germans' unrestricted submarine warfare that had devastated the US' shipping in the Atlantic Ocean and continued to gather sympathy for the Entente's causes when President Woodrow Wilson was elected to office. Upon the reveal of the Zimmerman Letter, this had convinced Washington that the US needed to go to war against Germany and so, the US would join the Entente in 1916-17 where their massive pool of resources would relieve exhausted Entente troops.