Schlieffen Plan
Richard Brooks in 2000, wrote that the significance of the battle centres on its undermining of the Schlieffen Plan, which forced Germany to fight a two-front war against France and Russia—the scenario that its strategists had long feared. Brooks claimed that, "By frustrating the Schlieffen Plan, Joffre had won the decisive battle of the war, and perhaps of the century". The Battle of the Marne was also one of the first battles in which reconnaissance aircraft played a decisive role, by discovering weak points in the German lines, which the Entente armies were able to exploit.