With all the publications on the centenary of World War I that have emerged over the past few years, there has been a focus on the forces that led to 1914 and the beginning of another thirty years of mass murder across the European continent.

Although the roots of this European suicide can be traced back over centuries, the first half of the twentieth century also came to signal the emergence of the United States as a global power. It was already visible in the trumped up war with Spain in 1898 and later after the turn of the century as U.S. leadership began to extend its vision of manifest destiny to a global stage. The military occupation of the Philippines continued the self-perception of the United States having a global mission, which it had already projected into Central and South America in the nineteenth century.

Yet, despite this show of imperialist aspirations with military muscle-flexing, the dark clouds on the horizon in Europe during the years prior to the summer of 1914 were seen by a good majority of Americans as something in which they did not want to get involved. The European conflicts were worrying but not so much as to require American engagement. When war in Europe did break out, most Americans were inclined to view the matter as something Europeans would need to settle. Americans might admonish Europeans and some might even reflexively support the British and their allies against the Central Powers. But it would take another three years before the United States joined the war effort and turned the tide to help defeat Germany.

Erik Larson’s latest book Dead Wake tells part of that story largely by focusing on the fateful trip of the Lusitania in 1915 on its voyage from New York to Liverpool. Sunk by a German submarine off the coast of Ireland, the ship was the catalyst that set in motion the steps President Woodrow Wilson was to take to ask Congress for a declaration of war against Germany in 1917. In that interim period, German submarines sank a good deal more ships. But the Lusitania had claimed over 125 Americans civilians—some very prominent—who perished along with over a thousand others. The anger with Germany began to boil.

Yet even amid these losses on the high seas, the American public had not reached fever pitch until another catalyst occurred, which brought Wilson to the point of no return. That was the infamous telegram by the then Minister of Foreign Affairs in Berlin, Arthur Zimmerman, delivered to the Mexican government. In that telegram, the Minister proposed an alliance with Mexico to help defeat the United States, should it enter the war on the side of Britain. And as a part of that bargain, following a joint victory, Mexico would recover its “lost territories” in the U.S.: Texas, New Mexico, and Arizona.

That additional provocation brought Washington into the war as much as the Lusitania did.

As we learned in Larson’s last book In the Garden of Beasts, the author has a particular talent for describing the environment of the world he illustrates by focusing on particular personalities as they are impacted by events around them. The book follows the captain of the Lusitania as well as the captain of the submarine that fired the torpedo. It also focuses on the trials and tribulations of President Wilson in dealing with the decision to eventually go to war with Germany. Finally, it focuses on a secret intelligence operation in London that was instrumental in understanding what went on before the U.S. entered the war.

Even though we know what is going to happen from the opening pages of the book, the descriptions of people’s motivations at the highest level of government down to the passengers on the ship and the submarine capture the forces that were driving Europe, and eventually the United States, into a war that caused millions of deaths. Even though it was “the war to end all wars,” it was only the beginning of a conflict that would lead ultimately to a second world war costing even millions more lives.

The book describes the motivations of those who prepared for war, those who tried to avoid getting involved in war, and those who were more obliviously threated by war. It is a story of something which many believe was a major catalyst for the U.S.’ entry into that war, but was in fact one of many post signs along the way toward it.

While one knows the outcome before the book begins, it is an exciting tale of how people judged and misjudged their steps along the way to a catastrophe that could have been avoided, but, for all the reasons Larson describes, became inevitable. In that sense, it remains a warning to those searching for those post signs today.