Did Germany's role in WW2 affect the historical perception of its role in WW1?

The German role in World War I was "bad enough," even without being further tarnished by World War II.

German atrocities in World War I included 1) the occupation of Belgium, 2) unrestricted submarine warfare, and 3) poison gas. As another poster pointed out, the Germans not only occupied Poland, but had plans to "depopulate" the country for German settlement.

With the notable exception of poison gas, all of these actions had echoes in World War II. The remaining three actions targeted civilians (although tales of rape in Belgium are largely false, the Germans rounded up and shot thousands of Belgian "hostages." Targets of submarine warfare included passenger liners such as the Lusitania. And beginning in 1915, Germany despoiled Poland of its harvests.

Perhaps World War II represented an "Aha" moment for some people who had earlier suspected that the Germans were the bad guys, and now felt "sure." One could say that the the German posture in World War I was a "precursor" to that of World War II.

Oh absolutely.

Germany was without question the bad guys in WWII, so people naturally assume they were the bad guys in WWI too.

But the reality was, there were no good guys during WWI.

It was a bunch of imperial/colonial empires fighting each other in a giant game for world domination.

In the end, they all did such great damage to each other that virtually all the old dynasties collapsed, and set the stage for self determination of people on 5 continents today.

But the European dominance was so strong that those recalcitrant slow learners had to give themselves a true coup de grace with WWII, which finally completely finished off the European centric world that their forefathers spent 4 centuries to build, to finally free the world of their dominance.

A study of WWI is a study of the European mentality. And trying to get the moral high ground 100 years on is just an extension of that thinking.

Note: The European leaders cared nothing for their own people either. If it wasn't for the fact that the regular soldiers were in open revolt, and the population at home was starving, the ruling elites would happily let the war go on indefinitely.

The ultimate result is, while millions died, the world wars did end the tyrannical rules of the european monarchies.

As German my perspective:

Sure WWII influenced the role of WWI for the coming generations. Once you get the role as baddie, it is quite hard to get away from the image which is quite understandable for the reason that Germany played the main role in two(!) of the biggest wars ever known. It is even more understandable because in the second case Germany acted like a real villain.

But, and this is a big but, the perception of history is influenced by the winning powers.

You asked about WWI and as some answers want to paint Germany as baddie, too, so I feel compelled to give some counterpoints. Because it is quite a tragic incident, I will tell it with a spoon of black humor.

Denis answer about the arms race are straight to the point, but the brazen rhetoric and arrogant, haughty behavior came after Bismarck's dismissal. Bismarck had built before a network of pacts and relationships which were neglected and antagonized the other nations with the behavior. Everyone believed that the own nation was superior and should lead the other nations (imperialism, wink, wink), but Germany was the only one who informed the other nations of this attitude. Essentially we sucked big time at diplomacy, but we were also a militaristic power which was growing alarmingly strong.

The last fatal mistake was giving Austria-Hungary (which was also a fledgling power because it was a state with many nationalities) carte blanche and allowing Austria to threat Serbia and its protector Russia, so that really every major power was antagonized.

What happened now is important: Nobody knew or expected what was going to happen. War was romanticized (Paintings, games for boys etc.) and seen as a valid political option and a power contest, it was also often quite restricted in dimension and time. The parties should have looked at the experiences of the technological American Civil War which was quite a warning about the new massive defensive capabilities. There were nobody saying at this time (or at least meaning) "German is waging a war of aggression!". If you see the images of soldiers it looked like they were going to a holiday. Kick the other's nations ass, get the capital city and everything is fine.

Now to the bad reputation.
After a short time it was clear that it will end in a two-front war, something which Bismarck wanted to avoid at all costs and also the German commanders knew that time were working against them. So they wanted to throw down France as fast as possible. The idea of the Schlieffen plan was to flank France through the occupation of Belgium. Some background information which is conspicously missing: During the 1871 campaign German command experienced strong resistance by partisans (franc-tireurs) which resulted in brutal retaliation. Fearing that the march through Belgium could be contested and delayed, the Germans reacted with excessive force of real and imagined attacks: mass executions and burning down of whole villages, especially Dinant and Leuven. But during the 1871 war the very same, but rarer brutal reprisals were irrelevant for England because France was the archenemy, but now as ally the real atrocities were not even enough: The English press and offical channels invented fairy tales of horrors. Babies spiked on bajonets, women hacked to pieces or breasts cutted off, little girls raped, little boys maimed on hand and feet, nuns tortured and bound on bells. The bloodier and gorier, the better.

But at least it seemed to be not enough: During Christmas 1914 it came to completely unexpected scenes of affection between the trenches. Sure, the British and French soldiers couldn't be that dumb to give child-raping mutilators a present? But they did.

I do not need to describe the horrors of gas warfare and the infamous role of Fritz Haber (His wife, a pacifist, committed suicide after the first gas attack). But I wonder if anyone still knows what "défaitisme" (defeatism in english, Defätismus in German) means and how it was used. If you search for it seems to be only a word for hopelessness and giving up.
After the failed Verdun attack (it was called Blutmühle, blood mill) the Germans realized that artillery and mass attacks are simply idiotic and prone to fail. So they concentrated their powers on the East front and built a deeply connected system of fortifications, the Siegfriedstellung or Hindenburg line. During 1916/1917 hundred of thousands French and English soldiers were killed in senseless attempts to take the line with the methods which were shown to be ineffective. The generals did not care a bit, they were exactly as evil, ruthless and uncaring as the purported Germans. The Germans named the soldiers Löwen, die von Eseln geleitet werden, lions led by donkeys.

Finally, in the first half of 1917 the soldiers were breaking. Whole divisions stopped fighting and obeying commands. The generals denied any responsibility and accused the soldiers of cowardice and defeatism and started to kill their own soldiers in trials and cruel punishments. This unjust treatment was simply eradicated from WWI history.

Breaking rules of war.
It would be interesting if the naval blockade of the United Kingdom is mentioned in the history books. GB was infamous for "paper blockades", saying e.g. that France is now "blocked" and this gives them the right to stop any merchant vessel (even in the middle of the Pacific) and search and confiscate any "contraband" which could be targeted for France (often without compensation). Many nations balked until finally 1856 the Paris Declaration was ratified, including England. This makes on point 4 explicitly clear that a blockade needs to be in the vicinity of the coast to be binding. This was further clarified 1907 in the Hague Convention and ironically 1909 an even better protection suggested by the Britons in London (the London Declaration) was never ratified.

Great Britain violated international law by declaring 1914 open water outside the territorial waters as "War Zone" and despite the explicit prohibition to block anything apart from belligerent material the Royal Navy also confiscated food and fertilizer, knewing that it would cause famine in Germany.

They also knew it because the blockade was incomplete during the first months because they feared to aggravate US merchant vessels. Only after the horror stories of Belgium (remember, many of them purposefully invented) was beginning to take effect, the US allowed the full blockade.

The RMS Lusitania which was blamed as attacking an innocent vessel

• transported war material (munition)
• the ship used contrary to naval law no flag or even the US flag (!)
• the Admiralty gave the order to evade U-Boats or trying to ram them, in contravention to the Cruiser Rules.

so in essence the ship was a valid target as blockade runner. And the Lusitania was no exception, strangely everyone remembers the unrestricted submarine warfare, but nobody seemed to notice that Great Britain threw the rulebook of naval warfare into the water.

Racism and imperialism.
Racism was alive and well during the beginning of the 20th century and Germany was neither an exception nor outstanding in this regard. So accusing them of evil thoughts was ridiculous as any culture can testify which had the dubious pleasure to be civilized by colonial powers. Pointing out the Hun talk of Emperor Wilhelm was first-class hypocrisy because every colonial power was committing atrocities in China. And if someone think that Great Britain belongs to the good guys may be reminded what happened one year later.

Endpoint
After the horrific war the original viewpoint had deeply changed. It was such an amount of devastation and loss of life that the remaining people were simply stunned. The romantic ideal of war had died. As humans are, they were searching someone who was responsible and Germany was easy to blame. While Germany started the fire, it was definitely not the evil Hun as it was painted by the Allies and the Allies were not so good and blameless as they wanted to be seen.

In popular culture, absolutely. Among historians, not so much.

I stumbled across a 12-volume history of the "Great War" at a garage sale some time ago. The tone in this series is grim but grounded. The Germans are considered the aggressor, a dangerous enemy, and possessed of few (if any) scruples. I doubt anyone would publish such an extensive series today, but if anyone felt that an update was necessary, I suspect that the tone would actually be more sympathetic to the Continental powers. Today's historians are an equivocating lot, quick to accept (or at least, repeat) the arguments of the apologists of even the most odious regimes. Decades of Cold War conflicts in places like Vietnam, Suez, and Nicaragua have trained scholars to put democratic and absolutist regimes on the same plane and to find the seeds of conflict in economic and class issues. The tendency among modern historians to call for "a pox on all their houses" is much stronger today than before WWII.

But whereas historians tend to be just a little kinder to the Germans today, in popular culture the opposite is true. The depiction of the Germans in Wonder Woman is certainly the most appropriate example at the moment. There are two reasons for this. First, WWI is barely taught in American schools today and most Americans conflate it with WWII. And about the only thing the average American knows about WWI is that the Germans used poison gas and sunk the Lusitania with a submarine. These do not give Germany a positive image (although the Germans also had zeppelins, which really looked cool.) Finally, to most Americans, WWII was just Germany's "second try".

A nice example from the popular culture of the 1960s is the Tom Lehrer song about the MLF (Multi-lateral Nuclear Force) being mooted at the time.

Once all the Germans were warlike and mean,

but that could never happen again.

We taught them a lesson in 1918

and they've hardly bothered us since then!

That line still gets laughs today, although a large part of the audience today would wonder what happened in 1918.

During WWI Germany show some signs of what later would be labelled as Nazism.

General von Kries governor of German occupied Poland said:

In Poland, in the midst of a dying nation. Germany is destined to rule the world, or at least a great part of it. The German people are so much human material for building the German state, other people do not count. All is for the glory and might of the German state. The lives of human beings are to be conserved only if it makes for the state's advancement, their lives are to be sacrificed if it is to the state's advantage.

"Partitioned Poland" article in National Geographic by William Joseph Showalter, Frederick Walcott writes about his conversation with then general governor of Poland, in which he explained the plans to exterminate Poles though starvation:

"General, I cannot discuss this thing with you ; it is worse than anything I ever heard of. I did not suppose any civilized nation would be guilty of such a thing as this" ; and I started to walk out. said, "Wait a minute : I want to explain this thing to you. We do not look at it as you do. Starvation is a great force, and if we can use that to the advantage of the German Government we are going to use it." "Furthermore, this is a rich alluvial country. We have wanted it and needed it for a long time, and if these people die off through starvation, perhaps a lot of German people will overflow into this country and settle here; and after the war, if we have to give up Poland, the question of the liberty of Poland will be solved forever, because it will be a German province.""

There was simillar statement about the future of Belgium by General von Bissing:

"If the relief of Belgium breaks down we can force the industrial population into Germany through starvation and colonize other Belgians in Mesopotamia, where we have planned large irrigation works; Germans will then overrun Belgium. Then when the war is over and freedom is given back to Belgium, it will be a German Belgium that is restored. Belgium will be a German province and we have Antwerp - which is what we are after.

WWI could also be seen as a fight between good and evil. Germans had plans to exterminate large number of inhabitants of conquered countries trough starvation and colonized them the with Germans.

the Germans are treated as the bad guys

That line of thought is not without reasons. Simplistically:

The world order before WW1 had the UK copping the seas. Germany sought to challenge the UK's naval supremacy and engaged in a naval arms race with them. This led the UK to bury its hatchet and cooperate with France, its historical rival.

Germany had no shortage of brazen rhetoric and behavior in the years leading to the war. In 1905 Wilhelm II came to Tangier and denounced French influence in Morocco. Edward VII denounced it as "the most mischievous and uncalled for event which the German Emperor has been engaged in since he came to the throne." There was another major Moroccan crisis in 1911 when Germany sent a gunboat to Agadir.

The weeks leading to the war are also worth a mention. Wilhelm II offered unconditional support to Austria. They later sent ultimatums to Russia (who was pre-mobilizing) and France (who had made its support to Russia clear). France was required it to stay neutral in the coming war and hand over some border forts as a guarantee - i.e. not acceptable. Then, anticipating that Russia would declare on Austria to defend Serbia, Germany declared on Russia. And anticipating that France would back Russia, it declared on France. The UK entered the war over Belgium the next day. It's worth noting here that these events all occurred before Russia had actually come to Serbia's rescue against Austria; it actually was Austria that ended up declaring on Russia two days later.

Austria was not without fault of its own. In particular, it sent Serbia a humiliating ultimatum. Each of its points basically got accepted except one. (Some historians disagree on how to interpret Serbia's reply. Clark in particular described it as a "highly perfumed rejection on most points.") Either way, Wilhelm II commented that it's "a great moral victory for Vienna, but with it, every reason for war disappears." Austria went on to declare war on Serbia regardless.

So, put another way, Germany (and Austria) had an aggressive attitude before the war. And while Austria fired the first shots by declaring war on Serbia, it was Germany that ultimately lit the powder keg in anticipation of the subsequent reactions. As such, thinking of them as the bad guys isn't that big a stretch, and the Treaty of Versailles enshrined this with a (controversial) provision whereby Germany accepted the responsibility for causing the war.

is it possible that the history of WW1 as taught after WW2 was strongly colored by WW2?

It was, in the sense that WW2 removed any lingering doubts on how post-WW1 treaties left (or indeed created) a lot of unfinished business. There still is some today - in Hungary for instance. It also brought to light the need for reconciliation.