How many mistakes can you make, when seen in hindsight, before the world falls in on you?  German leadership at the beginning of World War I didn’t think that the British would come into the war.  They thought that France would crumble as quickly in 1914 as they did in 1871.  They didn’t think that the Russians would be able to bring their armies into the field in time to stop the German juggernaut.

Finally, and fatally, they didn’t think that any of the neutral countries would respond when German U-Boats began sinking their ships.   The sinking of American shipping in 1915, 1916, and 1917 was probably the one big casus belli for the United States, a nation that had only recently gotten involved in any overseas conflicts, into the war.

On February 4, 1915, the German government declared a policy of unrestricted submarine warfare against shipping that appeared to be headed for Allied ports.   The Germans discarded the gentlemanly practice of forcing a merchantman to stop, allowing the crew and passengers to escape on lifeboats, then sinking or capturing the ship, assuming that it did indeed carry war goods for the opposition.  Rather, German captains began to torpedo merchant vessels without warning or inspection.

Was this practice more horrendous than the slowly-tightening noose of blockade that was around the neck of the German populace?  That’s debatable, but the British blockade did at least have the effect for which it was designed.  German torpedoing of commerce between North America and Europe brought hardship and hunger to the British Isles, but I’ve seen nothing that it ever approached bringing Britain to her knees, and it certainly didn’t shorten the war.  It did, however, enrage neutrals like the United States, and eventually brought the reinforcements the Allies desperately needed into the war.