Politician, Cultural, and Economic effects on the USA if they never join WW1

I don't think Wilson was expecting major battles in Latin America the day after the war ended or anything that drastic, certainly the Military and Naval expansion authorised in 1916 had a 5 year schedule for completion. Rather I think that instead of a benign Britain in effect enforcing the Monroe Doctrine the US would have to deal with Germany who might well do similar interventions as the US in support of its business interests, or picking sides during instability and supplying assistance to that side during the 20s.

And how, exactly, are they going to do that when the track record for trans-hemispheric interventions up to that point and even in that period is pretty abysmal without a pre-existing friendly power to operate out of? If the US is genuinely worried about Germany mucking around in the Western Hemisphere it won't take much to keep the Germans on their side of the Atlantic through a combination of diplomatic action, pressure on Latin America (which is much easier for the US to exert in every way) and already having a head start on coupled with far greater capacity for building up a sufficient navy to keep it that way.

You're also ignoring that a victorious Germany is going to be too busy securing Mittleuropa, most likely intervening with mixed or disastrous results in the Russian Civil War, keeping Austria-Hungary from going down the tubes completely and stabilizing their position in Africa. They won't have the time, inclination or resources to do anything regarding the Americans beyond making funny faces at the US and if you've got a situation where the US is staying out of the war that's going to be in part because German foreign policy would be actively seeking to avoid antagonizing America. It's also a very ahistorical assumption to say the US depended on benign British assistance by this point in time to maintain the Monroe Doctrine. That was true during the early to mid 1800s when it really did depend on the Royal Navy to make possible but by the time of the Spanish-American War and the launching of the Great White Fleet the United States was more than capable of doing so without any assistance with no real debate from the rest of the planet.
 
And how, exactly, are they going to do that when the track record for trans-hemispheric interventions up to that point and even in that period is pretty abysmal without a pre-existing friendly power to operate out of?

As I said, I don't think Wilson was expecting battles with Germany in Latin America, however Germany can quite reasonably and legally supply Latin American countries with arms and the like during peacetime as part of normal inter-state commerce. In times of instability it could supply arms to whichever side best suited German interests, meaning that a US intervention would face tougher opposition. Germany could also make large strategic investments in things like Mexican or Venezuelan oil and be reasonably expected to vigorously defend such crucial interests, which again would be a different paradigm for the US compared to the general benign cooperation with the British.

You're also ignoring that a victorious Germany is going to be too busy securing Mittleuropa, most likely intervening with mixed or disastrous results in the Russian Civil War, keeping Austria-Hungary from going down the tubes completely and stabilizing their position in Africa. They won't have the time, inclination or resources to do anything regarding the Americans beyond making funny faces at the US

I'm not ignoring it, I just think such claims are overblown in the short term and irrelevant in the medium-long term. IOTL Ober Ost was secured by 25 of Germany's 251 divisions in 1918-19, hardly a crippling burden and one that would reduce over time. Sure, there will be chaos, but the US Defense Act was a 5 year plan, by 1921 Europe will have settled down, Germany's political system will have been reformed (ending of Prussian 3 class franchise) and Eastern Europe will be in a political system far freer than what they were used to under the Russians which will lead to plenty of people cooperating with the new regimes.

US is staying out of the war that's going to be in part because German foreign policy would be actively seeking to avoid antagonizing America.

To an extent yes, but certainly the war situation that IOTL lead to Germany antagonising the US would be different considering the Germans both won the war and avoided antagonising the US.

It's also a very ahistorical assumption to say the US depended on benign British assistance by this point in time to maintain the Monroe Doctrine. That was true during the early to mid 1800s when it really did depend on the Royal Navy to make possible but by the time of the Spanish-American War and the launching of the Great White Fleet the United States was more than capable of doing so without any assistance with no real debate from the rest of the planet.

By 1914 the British weren't enforcing the Monroe Doctrine with warships, but by not having conflicting interests with the US which would cause problems when the US wanted to intervene in Latin America. This would most likely often be the case with German and French interests as well, but in situations where it wasn't the case frictions can occur. In a victorious Germany 20s such frictions might have to be handled differently due to German power.
 
The Ottomans will probably regain Great Power status once they discover the oil in what would be Iraq and Kuwai and they'd probably squash the Sauds with their Rishidi allies, meaning the Rishidis will control Arabia and discover the vast oil
 
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