[Working backward from the year 2000 toward America’s beginnings.]
World War I was already nearly three years old by the time America entered in 1917. Wilson had been re-elected in 1916 under the slogan “he kept us out of war,” because, arguably, a different president would have asked for a declaration of war against Germany in 1915, after a U-Boat sunk the Lusitania off the Irish coast, incidentally killing more than 100 American passengers. Many decades later, pretty good evidence began to suggest that the British Admiralty, led by a young Winston Churchill, deliberately placed the Lusitania in harm’s way in hope that a U-Boat sinking would bring the United States into the war on the Allied side. Had it not been for Wilson’s determination to preserve his nation from becoming enmeshed in the war, it might have succeeded. His diplomatic notes to Germany, carrying with them the implied threat of American intervention, resulted in a German pledge to abandon unrestricted submarine warfare, which it honored until the beginning of 1917.
This is of unrestricted submarine warfare involved two issues, rarely disentangled and understood today.
The first, sinking commerce without prior warning, was mainly an emotional issue, and it was a logical result of the limitations of the submarine. Prior to the invention of the submarine, there were well understood rules for commerce raiders. One of those rules was that ships’ crews be allowed to put off in lifeboats, which of course involved warning them. But a few months of experience demonstrated that this was too dangerous for the lightly armed submarines, which, surfaced could be heavily outgunned by even freighters. Submarines began to attack with torpedoes while submerged, hence, without warning. Thirty years of warfare accustomed us to this state of affairs, but to a world accustomed to prewar standards of civility, it came as a shock. British propaganda maintained that sinking ships without warning was German barbarism. It wasn’t. It was what the technology dictated. Twenty-five years later, American submarines in the Pacific would do the same thing for the same reason.
The second issue, though, was less technological than political and strategic. That was the designation by the German high command of an extensive area around the British Isles within which any ship of any nation, Allied or neutral, was liable to being sunk. This was the logical counterpart to the British – the Allied – policy of total blockade of the Central Powers, which, in effect, meant Germany and the territory it had occupied. The British Navy ruled the oceans; it was able to restrict neutrals’ access to German territory by forcing all shipping to submit to search and, if ordered, proceed to London. The comparable German response was undersea warfare, which by its nature did not allow for searches or for redirection. The two alliances were trying to starve each other into submission, and Britain, which required vast amounts of imported food and other resources, was particularly vulnerable to being strangled by sinkings.
In 1915, President Wilson used his leverage to bring the Germans to abandon unrestricted submarine warfare rather than add the United States as another, and most formidable, adversary. But by 1917, the German Empire was forced to gamble that unrestricted submarine warfare could starve Britain out of the war before American military might could be developed and brought to bear. So, once again German U-Boats were sinking anything in sight, regardless of neutral status. So President Wilson, against his will and within a month of his second inauguration, asked Congress for a declaration of war. (That night, when he had returned to the White House, talking to someone about the Congressmen’s collective reaction, he said how strange it seemed to him that they should be cheering an action that must result in the death and mutilation of many thousands of young American boys. And then he began to weep.)
But now America was in the war, and rather than try to keep up the people’s morale by economic explanations (that is, what would have happened to the country if our commerce had been swept from the North Atlantic, and if the British and French should lose the war and default on so many debts they had contracted for war materials), Wilson explained that we were now fighting to defeat Prussian militarism. This, he said, was a “war to end war.”