Analysis of two branches of the USE timeline I keep posting about, specifically the war with GB.

If I don't try military buildup first

War starts in1892. Spain, Russia, and US join my side. I can hold against their naval invasions, but I can't counterattack and Russia just so happens to have a revolution that our remaining forces can't defeat. (This also happened in my India run.) Best I could manage before Russia imploded was getting them to 0 war support, but I couldn't white peace.

If I do try military buildup first

War starts in 1891. Spain and Russia join my side, but US joins Britain. As you might expect, naval invasions everywhere under the sun, but we held them off. Continued to build up as Britain neglected to attack me, praying for a naval invasion success. Other fronts have slowly ground down, except in Africa which is a bit broken. A couple combatants had civil wars in the middle, thankfully not Russia itself but its subjects did. Eventually, America just capitulated.

A while later, our war participation was falling faster than Britain's, so I kinda panicked and ordered a Sealion: two naval invasions, one to the Highlands and one to Yorkshire. The Highlands one actually went through, so I sent in my big original army (on standby in case Britain naval invaded my mainland) and started walking down the islands. This caused the Brits to flip out and try counter-Sealioning, which failed due to yet another of the armies I had been raising, and I eventually took the home islands. The struggle for Britain was so bloody that it gave me the "All quiet on the western front" achievement for my efforts.

Been letting foreign countries invest into me basically the whole game, but now my GDP ownership is down to 71% and I want to know whether to tell them to sod off or not.

If my market matters, I expanded the Zollverein quite a lot and it now includes Sweden (who's had investment rights to me for a while and now owns 13% of my GDP) among other countries. Our biggest GDP state is Bohemia, by a long shot (probably due to having gold, big mines, and some company HQs), and its GDP is 64% nationally owned (one of those company HQs is Carnegie and they've been building steel galore).

EDIT: Didn't think this would be relevant, but I have a lot of money. Like, a lot. Been stockpiling for years and I'm raking in tens of thousands of pounds a week even with minimal taxes and max wages. At least currently, money is no object.

Already over 1 GDP per capita and best average standard of living I've ever had. (Ignore the prestige, it's from the Australian Unifier buff since I just annexed United Tribes.)

...and I think I'm to blame

Won the League war as MinGan, Liangguang flipped KMT on its own before I subjugated it, then managed to snag Yunnan just before Sichuan turned into a 4th government. Not sure when Zhili got Hunan.

Decided to post this since I'm working on a scenario myself that includes a reformed USSR.

The reformed USSR is not going to keep all of its republics. I will demonstrate using a map I got off of Wikipedia's article on the New Union Treaty, the thing meant to reorganize the Union of Soviet Socialist Republics into the Union of Sovereign Socialist Republics.

The ones in black didn't support the New Union Treaty before the August coup, the ones in orange supported before but switched after, and the ones in red supported both before and after.

• The Baltics were already agitating hard for independence in 1989, before the New Union Treaty came to be. Gorbachev's government knew that their departure was inevitable.
• Moldova was also preparing for independence in 1989, to the point where two different parts of it (Transnistria and the lesser-known Gagauzia) broke away to stay in the USSR.
• Georgia was split between Abkhazia and South Ossetia in the north that were pro-Union and the rest that were anti-Union, instead desiring independence so that they could integrate those two regions.
• Armenia was already not on very good terms with Moscow over the Nagorno-Karabakh issue. If they conceded to Armenia on that, the situation would just flip and it would be Azerbaijan not wanting to join instead.
• Ukraine and Azerbaijan already had lots of anti-Union voices, but the August coup was what made them flip for good.

The Baltics, in particular, did not like the Union at all. You would have to make significant historical changes to make them want to stay, and using military force would for sure draw large amounts of attention and ire from the international community.

I don't really think there's much that can be done to keep these republics in the reformed USSR, except maybe Georgia. If Georgia cannot be convinced, then Armenia would become disconnected from the rest of the USSR if they were favored in Nagorno-Karabakh, so keeping Armenia also requires keeping Georgia.