> *Why bother to launch an attack?*

First thing is to realize that strategic trench warfare in the Great War was not planned. It's [something that happened to prevent being strategically outflanked](https://en.wikipedia.org/wiki/Race_to_the_Sea). While trenches were used in individual battles prior, nothing like a deadlock on this scale had been seen nor even seriously considered before. Nor had the lethality of heavy machine guns, heavy artillery, and breech-loading magazine-fed rifles been accounted for.

Prior to the Great War, warfare was about small, professionally trained armies marching around the countryside in an attempt to trick the other side from accepting battle at a place of your choosing. The prior [Franco-Prussian War of 1871](https://en.wikipedia.org/wiki/Franco-Prussian_War) was fought with 500,000 men on each side compared to the tens of millions in the Great War. Battles would last a day or two and be sharp, decisive conflicts with one side holding the field and the other retreating. The [largest battle of the war at Gravelotte](https://en.wikipedia.org/wiki/Battle_of_Gravelotte) lasted just one day. Warfare was still mostly a matter of keeping your forces acting as a unit, answering commands, and not running away. Victory came from taking the initiative, and crushing the enemy's morale. Waiting for your enemy to attack you gave them the initiative which would mean defeat.

The army leadership was not ready for a continent-spanning trench line bristling with machine guns and high explosives. They lacked the training and tactics to deal with it.

And we've never seen its like since. A single, continuous, fully manned line is too costly and too brittle for the pace of modern warfare. The Great War taught the armies of the world how to assault a line, and it also taught defenders how to be flexible rather than be rigid lest they be outflanked and bypassed. For example, Finland's [Mannerheim Line](https://en.wikipedia.org/wiki/Mannerheim_Line) was really a series of mutually supporting bunkers, dugouts, and trenches. If an attacker overruns any one position, they will take fire from multiple supporting positions. If multiple positions are overrun, the defenders fall back to another line.

# For the French

If you're France and their allies, it's because you want the Germans out of France. The Germans aren't just going to just go away.

In any other situation you'd bypass a strong enemy position and cut off their supply. This avoids fighting the enemy where they're strong and forces them to come out to attack you. But the continuous line of trenches in the Great War made this tactical mobility impossible.

# For the Germans

If you're the Germans it's a bit more complicated. At the beginning of the war they faced the nightmare scenario of being pulled into a two-front war with France on one side and Russia on the other, something which previous German leaders had sought to avoid. Their initial plan, the [Schlieffen Plan](https://en.wikipedia.org/wiki/Schlieffen_Plan) was to knock France out of the war before Russia could fully mobilize and threaten Germany, mobilization in those days took weeks or months. Then they'd rush their forces from France to meet the Russians.

It didn't work out that way. The Schlieffen Plan failed at [First Marne](https://en.wikipedia.org/wiki/First_Battle_of_the_Marne) and all hope of outflanking the Allied lines was lost in the [Race To The Sea](https://en.wikipedia.org/wiki/Race_to_the_Sea). When [the Russians attacked East Prussia and Galicia](https://en.wikipedia.org/wiki/Russian_invasion_of_East_Prussia_(1914)) Germany still had the bulk of its armies fully engaged deep in French territory.

At this point the Germans were sitting pretty on the Western Front. If they wanted, the Germans could have defended their captured French territory until they could negotiate beneficial terms with France. Meanwhile they'd spend their offensive energy fighting the Russians. This would be the same basic plan, just reversed: hold off France on French territory, knock out Russia, then send troops west to defeat France. Add to this that the Russians were now deep in German territory.

And in many cases the Germans did. Germans on the Western Front generally considered themselves there to stay: they were sitting on captured French territory and didn't need to go anywhere. German trenches were relatively lavish affairs. In contrast, the Allies always recognized that they could not simply defend. They discouraged improving the living conditions in the trenches because they were always considered temporary; they didn't want the troops to get to comfortable. Of course this lead to poor sanitation, demoralization, bad food, disease, and death.

This might have been a sound change in strategy, especially since the [Eastern Front](https://en.wikipedia.org/wiki/Eastern_Front_(World_War_I)) offered more options for traditional warfare focusing on mobility rather than attrition. But the Germans never fully adopted this strategy. A lack of strong leadership at the top can be blamed for this, [Kaiser Wilhelm II](https://www.youtube.com/watch?v=EKe8WYiHCao) was a mediocre leader at best. He had a strong bias against and rivalry with the British, wanting to challenge their world spanning empire. But also the belief that France was the "real enemy" and the Russians should be negotiated with. Rather than look at the military reality, they looked at it politically.

Instead they fought on both fronts simultaneously, see-sawing between fronts, strategies, and crises. Once [the Russians were ejected from Germany in August 1914](https://en.wikipedia.org/wiki/First_Battle_of_the_Masurian_Lakes), the Germans focused on Russia in 1915 until they [forced a great retreat](https://en.wikipedia.org/wiki/Eastern_Front_(World_War_I)#First_combat_(August_1914)). Rather than press their advantage, they went back to the "real enemy", France.

His chief of staff [Erich von Falkenhayn](https://www.youtube.com/watch?v=xnwZjUrSc2k) held the belief that France was the traditional enemy of Germany, and that Germany and Russia had no real quarrel. This was the Germany political strategy prior to Wilhelm: keep Russia an ally to counter France. After the Western Front bogged down, Falkenhayn continued to believe they should defeat France militarily and negotiate with the Russians. In contrast [Hindenburg](https://en.wikipedia.org/wiki/Paul_von_Hindenburg) and [Ludendorff](https://en.wikipedia.org/wiki/Erich_Ludendorff) advocated attacking east. But Falkenhayn held the Kaiser's trust.

## Verdun: the Germans attack to get the Allies to attack

Falkenhayn's big strategy was to [attack at Verdun in 1916](https://en.wikipedia.org/wiki/Battle_of_Verdun). He originally pitched this not as a breakthrough attack, nor the battle of attrition it turned into, but as a way to force the French to counter attack against strong German positions. Falkenhayn intended to swiftly capture the strong positions at Verdun, then sit back as the French threw themselves at him. He figured Verdun was so important to the French they must attack, and that the Allies must make additional spoiling attacks to try to distract the Germans. This would drain Allied reserves from the rest of the front, thinning the lines for a German attack elsewhere. So in that sense, he was attacking at Verdun to force the enemy to attack him.

It didn't work out that way. The Germans failed to take Verdun. The Allies failed to thin their lines to reinforce it. It turned into a meat grinder. Rather than realizing his strategy had failed and halting his attack, Falkenhayn now claimed Verdun was always a battle of attrition and continued attacking. Always with this hope that the Allies would be bled white. He was replaced as chief of staff by Hindenburg.

## Too little, too late

Russia was eventually defeated in 1918. It did result in the Germans refocusing on France, though [leaving far too many troops to garrison their conquered Russian territory](https://en.wikipedia.org/wiki/Eastern_Front_(World_War_I)#Treaty_of_Brest-Litovsk_(March_1918)). But by then it was too late. Germany and her allies had been bled white. US troops were arriving to bolster the Allies. When the [German Spring Offensive](https://en.wikipedia.org/wiki/Spring_Offensive) hit the western front in 1918 they did so with new ["stormtrooper" tactics](https://en.wikipedia.org/wiki/Stormtrooper#World_War_I_assault_tactics). The Germans used [fire-and-movement](https://en.wikipedia.org/wiki/Fire_and_movement) to break the stalemate and finally got their breakthrough. But they no longer had the manpower to exploit it.