Let's assume that the United States joins the Central powers, while the Netherlands joins the Allies. My guess is that this would result in an Central Power victory, but I am actually curious about what territorial changes should I expect. Many threads talk about what the various central powers would take if they won. What I wonder is what should I expect the Netherlands to lose, and what would the Americans take?
For the sake of imagining any of this it is good to hear you have a TL going that can explain the reversal of the US position! By default the US coming in on the CP side is very unlikely, but if you can engineer hostility between the US and UK overwhelming the more natural ties toward alliance, fine.
What is much harder for me to imagine is the Netherlands daring to go against Germany. To be cool to hostile neutrals, perhaps...I can't see them being prepared to take on Germany in a knock-down fight. To be sure the Lowlands have defensive advantages, and with a reasonable generic war plan devised just in case (because this is what competent military general staffs do, not because anyone hoped for war with Germany) competently executed in a contingency where it is the Germans who go nuts and attack the Netherlands first, I might believe the Dutch planned defenses can check a German invasion (with lots of Entente help!) and retain control of much Dutch territory, and then usefully from the alliance point of view bog down crucial numbers of German troops not available for service elsewhere. However if the Germans are willing to see their advances in the east slowed down, they might be able to divert enough Eastern Front forces to hold the Dutch front, while maintaining OTL forces in France and Belgium. They cannot afford to relax or fall back on the Western front and we still have to offer a plausible reason for the Germans to attack the Netherlands.
To summarize, a neutral Netherlands was a valuable asset for the Second Reich, being an intermediary; remaining at peace with the Dutch got them access to Dutch colonial goods (insofar as British arm twisting permitted anyway), a quiet front, and the services of Anthony Fokker's aviation company which as famously known provided the German air forces with most of their best planes. A mad high command might believe they could seize the Fokker works intact (very dubious, I believe these were based in the western bastion part of the country) but they'd lost every other benefit for sure. Where is the gain for Germany?
And while conceivably the Dutch are quite angry at the invasion of Belgium (but patriotically, why should they be?)--but they've got that huge vulnerable border with Germany. It might be possible to save part of the Netherlands from Belgium's fate, but the outcome would be nasty for the Dutch. As neutrals, the Netherlands could profit from selling to both sides, as Fokker's career demonstrates. So where is the gain for the Netherlands? Even if they could annex all of German colonial territory in the Pacific (but no, Japan would preempt them, or at least demand a split) what would that be worth to them?
I don't see the point of throwing the Netherlands in to the fray, except perhaps to give the Americans pretexts to plunder Dutch Caribbean and South American possessions. Again though, if the USN must fight its way through British elements in the Caribbean and Atlantic, not to mention being largely preoccupied with attempting to conquer Canada, if Americans can win that fight surely they have much richer prizes to take first--Jamaica, the whole sweep of both British and French Caribbean holdings, the islands of the Atlantic--is it really necessary to round them out with Dutch holdings when, assuming the USN can prevail, the whole of the Caribbean becomes an American lake anyway? We didn't need oil, we had domestic sources aplenty, and postwar might be in a position to extort the Dutch to sell. Or, with the Entente powers crushed, unilaterally invade at leisure.
The USA as it was OTL in 1914 of course had zero inclination to fight the Entente, and zero need to. And zero, essentially, except for having a pretty good navy, preparation to be able to either. Throwing the USN as it was OTL in 1914 against the RN one on one would be a hard fight for both sides--if the German HSF is also thrown in I give the CP/US alliance pretty good odds to prevail against the combined British and French forces. But it will be no cakewalk.
The variable here is that given deteriorating US/UK relations going back to the previous century, presumably the USA would build up forces much greater; this would come at a high cost to civil society and requires a hell of a motive to sustain. There is some question whether the USA would develop its OTL tremendous potential if leaders "cash in" on a big military, and to what degree society would be so different we can't extrapolate what Americans would actually do in a given situation. OTL, American military before WWII tended not to perform nearly as well as one would guess just by counting soldiers and adding up their guns. Gradually, as Americans were engaged, they would shake down to first rate quality and then their advantages in numbers and logistics would kick in full force; the longer the war goes on, the more unstoppable they become. But in an ATL where we arm to the hilt and go looking for a fight it might be quite different; we might start out near a lower peak and not push past that, deteriorating instead of hardening with time--a lot depends on morale, "what the hell are we fighting for?" A more authoritarian society might much reduce that variable, at the cost of losing an edge of commitment to win in a fight where the soldiers become persuaded of their own free will that they should and will win.
So the USA might enter the decade of the 1910s much better prepared--which is also to say that top of the line kit circa 1908 is dated in 1914, and it might be harder to transition over to the better stuff as fast.
Meanwhile--the British are going to know all this arming is aimed at them. They will evaluate their situation, take steps to make Canada and the waters around the USA more formidably defended. Indeed if they become persuaded the USA rather than Germany is the chief threat they face they might be more conciliatory to the Reich and come to agreements with the Germans that defuse the whole continental situation; the Germans are still going to worry about what happens when as feared, Russian quality of arms multiplies quantity well enough to pose a serious threat, but if they know the Franco-Russian alliance will not include Britain, they might have less of a fatalistic fear that war is inevitable and they must win it before the balance of power becomes unfavorable--therefore the Great War might be postponed, perhaps forever.
Here the assumption seems to be that Britain fears both Germany and the USA. Their most rational and simple recourse is to end the quarrel with America, and so I don't think a single diplomat being "indisposed" would change the course of their diplomacy much; they'd have to have a run of doggedly incompetent ministers to sustain the beef with the Yankees. Americans may be the uncontrollable variable, refusing to make peace--but if so, I think a separate war will break out earlier. Obviously the smartest thing for Americans to do is to sit it out and wait for the Empire to become entangled in some big mess, and then swoop in, but seeing the Americans lurking on the sidelines the British will trim their sails so as to minimize risk--unless they calculate that striking sooner rather than later is best for them. Even with all the admiralty and army brass in perfect agreement that war before it is too late is their best option, can British society be so persuaded? Presumably aggressive Americans are creating incidents that could precipitate a plausible war all the time.
Now say a tense situation exists, the Austrian archduke is killed, etc, and the Russians mobilize, then the French while Austria and Germany also mobilize. Given that Britain is distracted by the American threat, perhaps instead of having an alliance against Germany with France, Britain has stayed more neutral, eyes shifting back and forth across the Atlantic. Mightn't it then be more worthwhile for the Germans to attack the French frontier directly, instead of trying to cut through Belgium? OTL Parliament was on the fence until Belgian neutrality was violated; if that never happens, will Britain go to war at all? Can the Germans persuade the Americans to start their war and fight it alone, one on one with Britain? In that case the USA is only a "Central Power" in a very loose sense!
So this is definitely a low probability scenario. We need to know a lot more about how it got this way and what level of threat the USA represents.