Erik Sass is covering the events of the war exactly 100 years after they happened. This is the 271st installment in the series.  

March 21, 1917: Germans Withdraw to Hindenburg Line, Wilson Decides On War 

In the first months of 1917, the German Army achieved one of the greatest strategic surprises of the entire First World War with its successful withdrawal to a new, virtually impenetrable defensive line on part of the Western Front – called the Siegfriedstellung or “Siegfried Position” by the Germans, better known to the Allies at the “Hindenburg Line” for its creator, German chief of the general staff Paul von Hindenburg.

The plan dated back to Hindenburg’s ascent to the high command – aided as always by his close collaborator Erich Ludendorff, holding the title of quartermaster general – in August 1916. Shortly after assuming power, the duo cancelled the failed offensive at Verdun and decided to shorten the German lines on the Western Front by withdrawing from the area around the Somme, where two large German salients lay exposed to the north and south of the battlefield following the British offensive in the summer and fall of 1916. 

Both moves were part of Hindenburg and Ludendorff’s larger plan to shift the focus of the German war effort to the Eastern Front, the scene of their first great victory at Tannenberg, in the belief that a decisive victory over Russia was still possible, in contrast to the unbreakable deadlock on the Western Front. The withdrawal from the Somme to the new heavily fortified defensive line (in fact a whole network of trenches and bunkers) would shorten the front by 25 miles and free up 13 divisions for use elsewhere.

A vast system of trenches, barbed wire emplacements, and concrete dugouts and strongholds, stretching 85 miles between the towns of Arras and Soissons on the French side and in front of St. Quentin on the German side, the Hindenburg Line was largely completed in six months beginning in September 1916. Construction required 100,000 tons of cement, 12,500 tons of barbed wire, and vast quantities of rocks and gravel, filling 50,000 railcars and 450 large canal barges. A total of 70,000 laborers were employed in its construction, including 12,000 German pioneers, 50,000 Russian prisoners-of-war and 3,000 deported Belgian civilians (the latter two in violation of international conventions signed by Germany before the war). The project also required a web of new roads and railroads, power plants, water and sewage connections, and hundreds of miles of telephone lines. 

Unwilling to free the French population under their control, the Germans forcibly evacuated around 125,000 residents to other areas of occupied France, outraging public opinion in the U.S. (already moving towards war) as well as a host of other neutral countries. In order to slow the enemy advance and deny them any material advantage, the Germans methodically laid waste to the French countryside before withdrawing, destroying farmland, killing livestock, felling orchards, and burning villages – all of which proved another godsend for Allied propagandists. 

In his memoir “Storm of Steel,” the German soldier author Ernst Junger described the devastation:

The villages we passed through on our way had the look of vast lunatic asylums. Whole companies were set to knocking or pulling down walls, or sitting on rooftops, uprooting the tiles. Trees were cut down, windows smashed; wherever you looked, clouds of smoke and dust rose from vast piles of debris. We saw men dashing about wearing suits and dresses left behind by the inhabitants, with top hats on their heads… As far back as the Siegfried Line, every village was reduced to rubble, every tree chopped down, every road undermined, every well poisoned, every basement blown up or booby-trapped, every rail unscrewed, every telephone wire rolled up, everything burnable burned; in a word, we were turning the country that our advancing opponents would occupy into a wasteland. 

The Germans left behind thousands of booby-traps, according to Junger: 

Among the surprises we’d prepared for our successors were some truly malicious inventions. Very fine wires, almost invisible, were stretched across the entrances of buildings and shelters, which set off explosive charges at the faintest touch. In some places, narrow ditches were dug across roads, and shells hidden in them; they were covered over by an oak plank, and had earth strewn over them. A nail had been driven into the plank, only just above the shell-fuse. The space was measured so that marching troops could pass over the spot safely, but the moment the first lorry or field gun rumbled up, the board would give, and the nail would touch off the shell. Or there were spiteful time bombs that were buried in the basements of undamaged buildings... One such device blew up the town hall of Bapaume just as the authorities had assembled to celebrate victory. 

Geoffrey Malins, a British cinematographer filming the war for the British Army, left a similar portrait of total devastation (below, King George V visits the remains of Peronne): 

Not a tree was standing; whole orchards were hewn down; every fruit tree and bush was destroyed; hedges were cut at the base as if with a razor; even those surrounding cemeteries were treated in the same way. Agricultural implements were smashed. Mons en Chaussee was the first village we entered; every house was a blackened smoking ruin, and where the fiends had not done their work with fire they had brought dynamite to their aid; whole blocks of buildings had been blown into the air; there was not sufficient cover for a dog. 

The Germans abandoned their old positions along the Somme front in a carefully staged series of withdrawals beginning February 23rd, with the majority of movement occurring in a phased retreat from March 16-21, and the full withdrawal complete by April 5. Much of the withdrawal was conducted under cover of night and included numerous attempts at deception, including skeleton crews who remained behind until the last moment to keep up a screen of fire from machine guns, rifles, and mortars. 

In some places, however, the Germans couldn’t conceal their preparations for the pullback from Allied observers, presenting an opportunity for a bold attack taking advantage of the weakened defenses to disrupt the retreat and maybe even achieve a breakthrough. However Robert Nivelle, the new French commander-in-chief, remained focus on perfecting his upcoming April offensive, and on March 4 he rejected a proposal by General Franchet d’Esperey (nicknamed “Desperate Frankie” by the Brits) to mount a surprise attack with tanks, leaving the Germans to withdraw mostly unhindered (below, an aerial view of the Hindenburg Line). 

The British and French moved forward cautiously in the wake of the enemy retreat, taking in the horrors of no-man’s-land and devastation left behind by the withdrawing Germans. Philip Gibbs, a British correspondent, described German bodies left behind in what used to be no-man’s-land and the frontline trenches on the Somme battlefield north of Courcelette:

They lie grey wet lumps of death over a great stretch of ground, many of them half buried by their comrades or by high explosives. Most of them are stark above the soil with their eye-sockets to the sky… Their bodies or their fragments lay in every shape and shapelessness of death, in puddles of broken trenches or on the edge of deep ponds in shell-craters. The water was vivid green about them, or red as blood, with the colour of high-explosive gases… Where I stood was only one patch of ground on a wide battlefield. It is all like that, though elsewhere the dead are not so thickly clustered. For miles it is all pitted with ten-feet craters intermingling and leaving not a yard of earth untouched. It is one great obscenity, killing for all time the legend of war’s glory and romance.

John Jackson, a British soldier, recalled the ensuing advance into what were formerly German rear areas, where he saw huge barbed wire entanglements far behind the old front lines, on March 17, 1917:

The enemy had retired quickly and completely behind the line of the Somme Canal, leaving us nothing but empty trenches. It had been a cunning move and well executed… Except for occasional shells from long-range guns, which did no harm, the day passed over very quietly, while we advanced steadily, yet with caution, always on the look-out for a trap. The village of Barleux was entered without opposition and beyond it we came to the most perfect barbed-wire defensive system I had yet seen. It stretched to the right and left as far as the eye could see, and varied in depth from 30 to 40 yards. Composed of the roughest and most destructive wire imaginable, it would have proved a very serious obstacle to pass in a fight… In the darkness of night we could see the glare in the sky from great fires as the Germans burned the villages while retreating. 

Simply restoring communication and transportation links across the devastated area would be a massive task, taking weeks if not months of round-the-clock repair work – just as the Germans intended. Edward Shears, a British officer, described the preliminary efforts to make roads usable again in his diary on March 19: 

There was a belt of country three or four miles wide with literally no communications, and the work of construction involved was colossal… In places the road cleared easily. There were some six inches of mud and debris to scrape off, and then we came to the old surface unimpaired. Elsewhere shells had made large holes, and the job of filling these in was a longer one. 

The German withdrawal to the Hindenburg Line was better timed than they could have possibly imagined, as the sudden shift backwards helped disrupt the huge Allied attack planned by Nivelle for mid-April. The Nivelle Offensive, as it was remembered, would inevitably require massive artillery preparation and follow-up bombardments, calling for huge amounts of ammunition delivered by a fleet of trains and trucks; the German withdrawal dislocated these logistical efforts, forcing the Allies to improvise delivery of shells and other necessities on a large scale.

Even more importantly, Nivelle’s elaborate plan of attack (involving five French and British armies, numbering 1.2 million troops and 7,000 artillery pieces) depended heavily on detailed knowledge of the German positions and surrounding landscape for precisely calibrated artillery bombardments – an advantage which was now canceled out by the German move. In many places both the French artillery and infantry would be attacking unmapped, heavily fortified German positions, with predictably disastrous results. 

Wilson Decides For War

Even after the Zimmermann Telegram made headlines on March 1, 1917, outraging American public opinion, President Woodrow Wilson continued to move cautiously, apparently still unsure whether the United States was ready to go to war against Germany – or even that it was necessary to do so. However the events of the following weeks helped decide him on this fateful step, as the balance of public opinion finally appeared to shift towards war, thanks in part to fresh German outrages on the high seas. 

The sinking of U.S. merchant ships – the Illinois, City of Memphis, and Vigilancia – by German U-boats on March 16-18, 1917 seems to have settled the issue in the minds of Wilson’s closest advisors, including Secretary of State Robert Lansing and Wilson’s personal friend and confidante, Colonel E.M. House, who joined forces to persuade the president that the time had come. 

The sinkings were part of a sharp increase in losses since the resumption of submarine warfare in February, with losses set to soar in April, threatening to cut off American exports of armaments and bring the Allied war effort to a halt. Wilson’s decision to arm American merchant ships was a big step towards belligerent status, but the Germans would do everything within their power to avoid an open state of war with the United States – even if that meant losing a few U-boats to armed merchant ships, while continuing to sink hundreds more. 

Click to enlarge

Lansing argued forcefully for a declaration of war in a letter to Wilson on March 19, in which he noted that Germany and America were essentially already at war on the high seas: 

It will, therefore, be only a question of time before we are forced to recognize these outrages as hostile acts which will amount to an announcement that a state of war exists. I firmly believe that war will come within a short time whatever we may do, because the German Government seems to be relentless in pursuing its methods of warfare against neutral ships… 

As always, Lansing also framed America’s entry into the war as a blow for democracy, reflecting the patriotic idealism he shared with Wilson, including their desire to support Russia’s new “democracy”: 

… Entente Allies represent the principle of Democracy, and the Central Powers, the principle of Autocracy, and that it is for the welfare of mankind and for the establishment of peace in the world that Democracy should succeed. In the first place it would encourage and strengthen the new democratic government of Russia, which we ought to encourage and with which we ought to sympathize. 

Finally, a declaration of war now would secure America’s place on the world stage and ensure its participation in peace negotiations, where it could work to restrain the Allies from imposing a “vengeful,” destructive peace on Germany (left unsaid was the fact that American banks had loaned billions of dollars to the Allies, threatening financial and economic collapse if they lost).

Lansing also enlisted Wilson’s friend and confidante, Colonel House, to help persuade Wilson that it was time to act. On March 19 Lansing wrote to House: 

I have just returned from a conference with the President. He is disposed not to summon Congress as a result of the sinking of these vessels… I suggested that he might call them to consider declaring war, and urged the present was the psychological moment in view of the Russian revolution and the anti-Prussian spirit in Germany, and that to throw our moral influence in the scale at this time would aid the Russian liberals and might even cause revolution in Germany… If you agree with me that we should act now, will you not please put your shoulder to the wheel?

Finally on March 20 Wilson called a meeting of his cabinet, whose members spoke unanimously in favor of a declaration of war against Germany. The following day, March 21, 1917, Wilson called Congress into session eight months early, with a special session scheduled for April 2. While Wilson didn’t disclose his reasons for doing so, there could now be little doubt that he intended to ask Congress for a declaration of war. 

American Protective League Formed 

Even before the declaration of war, American society was changing under the pressure of events. On March 22, 1917 A.M. Briggs, a Chicago advertising executive, formed what was essentially a national vigilante organization, the American Protective League, to monitor pro-German opinion in the American public, prevent sabotage and strikes, and hunt down pro-German agents; later it would also arrest draft dodgers, infiltrate the labor movement, break up peace demonstrations, and enforce rules against hoarding – sometimes using violence.

Remarkably Briggs received authorization from U.S. Attorney General Thomas Gregory, who made the APL a semi-official adjunct of the U.S. Justice Department. Eventually the APL’s membership would swell to 250,000 people across the U.S., although not all of these were necessarily active “agents.” After the war, many APL members in the South joined the resurgent Ku Klux Klan.

See the previous installment or all entries.