When a war reaches the global stage, historians search for its long-term causes. Many look at the summer of 1914, a period that began with the assassination of Archduke Franz Ferdinand by Gavrilo Princip, a member of the Bosnian Serbian nationalist group known as the Black Hand. Princip’s act set off a chain reaction that saw the conflict escalate from a dispute between Austria-Hungary and Serbia into an all-out struggle for control of Europe.

The first major power to mobilize for war was not Austria or Germany but Russia, which feared that a victory by the Austro-Hungarians would give Germany and Austria an opportunity to attack it. The French were also encouraged to act because they wanted a chance to regain the territory of Alsace-Lorraine in southwestern Germany that they had lost forty years before and thought they could do so only with Russian help.

There was a great deal of macho posturing among the major powers, which exacerbated tensions. This was especially true in the case of Britain and Germany, which engaged in what has been called “secret diplomacy” to discuss their intentions and tactics. The military establishment was also gaining greater influence over public policy in Germany and Britain, as they built up their navies.

In the United States, President Roosevelt sought to extend a helping hand to the British, but the Neutrality Act and fears that America might be drawn into the war limited his options. He was also constrained by the fact that American soldiers and sailors were not prepared for war with Germany.