Greater Luxemburg

[wkwillis]

The Netherlands, Belgium, and Luxemburg stay one country. Succession rules are changed by the parliaments so that women can inheirit.The King or Queen decides that Luxemburg needs a bribe and sets up a national university there funded by taxes on coal, iron ore, etc. The university is a magnet for German students after the '48 and kick starts an industrial boom. The French technology goes to south Belgium where they speak French, the German technology goes to Luxemburg, and the Dutch still have their trading empire.
When the scramble for Africa gets going the Belgians still get the Congo, but the Luxemburgers get New Guinea. So Indonesia is Dutch, Central Africa speaks French, as in OTL, but New Guinea and the Pacific in general is where the Luxemburg German colonialists go.
Meanwhile the Belgians and the Dutch are just a little too big for the Germans to mess with after 1871. No WWI and WWII because the country isn't a small and easy victim. Britain stays out too, because Belgium isn't invaded. The German attack bogs down faster because the front is half as big and they can't maneuver around the French as in OTL because there's always another French soldier there, or behind the first one.
With Britain out, the German fleet doesn't have much use other than blockade. They might be able to block the Baltic and the White Sea, but not the Black Sea, or Iran if the Russians build a railroad there.
If the British lean towards the Russians, they might not be able to blockade the Russians at all without a war with Britain.

 

[Major Major]

So they stand on the defensive in Elsass-Lotharingen ("Alsace-Lorraine") and send the armies east to squash Russia. "Independent" Poland, Ukraine, Lithuania, Latvia, Finland in 1916-7. After heavy casualties pounding against the Sigfriedstellung, the French compromise, keeping Cameroon in return for recognizing the new countries.

 

[wkwillis]

So they stand on the defensive in Elsass-Lotharingen ("Alsace-Lorraine") and send the armies east to squash Russia. "Independent" Poland, Ukraine, Lithuania, Latvia, Finland in 1916-7. After heavy casualties pounding against the Sigfriedstellung, the French compromise, keeping Cameroon in return for recognizing the new countries.

Germany wanted to win, not to avoid losing. If they only liberate the eastern slavs from their overlords, where is their victory? Who is going to pay for the cost of the war? Only France and Belgium were rich enough to pay. All the eastern peasants had was wheat and potatos and sheep and lumber to compete with the wheat and potatos and sheep and lumber of the Junkers.

 

[jolo]

Originally, the Schlieffen-Plan was about attacking both Belgium and the Netherlands. They would still be a target, even if they were slightly stronger, and even if Luxembourg were stronger. The problem of those countries is, they are small and don't have much naturally protected areas like mountains.

Also, seeing how bad the French fared at the beginning of the war in OTL, they might even have lost, if the Germans had taken the southern route instead, as that would have left the French much less time to mobilize their reserves, and Germany would have gained access to the industrially important areas around Elsace-Lorraine, so that France couldn't have build up as much as in OTL during the war.

Luxembourg becoming a colonial power is unlikely, too, as it doesn't have sea ports.

The influence of a united Benelux might be much more interesting, especially between 1850 and 1900.

To Wkwillis: Weakening Russia was an important objective of WWI. And it would have been enough reward in itself. Getting former Polish areas, especially their coal rich areas in the south, would also be a nice reward, even if the rest of the freed territory gets independence to avoid the war getting too big. Furthermore, Germany wouldn't have minded a few states between Germany and Russia, even if it means giving the Poles their own nation a little bit east of their original home. But I must admit that the Germans were probably too greedy for a policy like that, as they refused a favorable peace with Russia in 1916 because they didn't get all the reparations they wanted...

 

[benedict XVII]

Well, I guess you assume Willem I is a bit smarter than OTL, and his kingdom doesn't break up. This said, Belgium (or Lux) didn't need anything in terms of French or German technology, thank you! Wallonia had the most advanced industry in Continental Europe OTL. If anything, the combination would have been even wealthier than the sum of its parts and taken a leading role in industrializing the rest of Europe. Also, Luxembourgers considered themselves very much Belgians during the first half of the XIXth century, unfairly detached from their fatherland in 1839 by the second Treaty of London. Their national identity grew only during the second half of said century, and became firmly established only during WWI. And, even if you'd add current Belgian Luxembourg to the OTL Grand-Duchy, you'd have a (sub-)country of about 150,000 inhabitants, with plenty of space: not clear how they could manage colonial expansion...

Keeping the Low Countries united is an interesting ATL indeed, but I think you make it more complicated than it should.