The Beginning of the Union
In this timeline Joseph Stalin has another son, Joseph Stalin II who will form this Union.
On the 2nd November 1963, at 3:15 in the afternoon the Warsaw Pact met in Moscow to enact the Act of the Union of Communist Republics (to form the UCR). Joseph Stalin II, a man who knew that the US would be enraged by this act, told all members of the Warsaw Pact to pretend they were still Independent, but progressively be absorbed entirely into the USSR (UCR).
Little did the people at this meeting know, a West German spy was overhearing and recording the whole conversation. A few weeks later the whole of NATO heard of this highly dangerous act and the USA, Canada and Britain secretly made a separate alliance called The Anglo Alliance, which also called for an Anglo Union if The UCR comes to fruition. On the 23rd February 1965 the UCR was officially formed as
the Union of Comintern Republics, although most people simply call it the Warsaw Union. although East Germany was kept as a puppet state to keep NATO from immediate attack, as NATO warned the new union not to annex East Germany for threat of Nuclear Warfare. Stalin II was declared the first Dictator of the Union. A new national flag is proposed, showing the desire for a Communist world, united under one flag. In the US the flag increases Paranoia ten-fold, as anyone even seen as a Socialist is expelled from The USA immediately. Students are taught that any foreigners (outside of NATO) are bad and are not to be accepted as Americans. The rest of NATO also enacts such laws, as Paranoia is seen as something to be encouraged.
The German Civil War
The German Civil War began on 15th June 1965 when disputes over who owned Germany in it's entirety boiled over into a full-fledged war. On 16th June 1965, 55 units and 15 corps equaling 1,350,500 men from East Germany and the UCR (all of current UCR troops at this point in this timeline are involved) are sent into West Germany as part of Operation Red Germany. NATO does not directly intervene as Stalin II warned that "We have our whole Nuclear Arsenal aimed at your most populous cities." NATO decides that they can only watch and give supplies and funds to West Germany, which they know is not going to be enough.
The end of and the Aftermath of the German Civil War
As of 5th August 1965, after just under two months of attempted and heavy resistance, West Germany falls to the UCA. Germany is Annexed in it's entirety to the UCA and the Treaty of Weimar (the last city left in West Germany) is signed by both parties. The Treaty states along with the annexation of Germany that certain parts of Austria are to be annexed and Austria itself becomes a puppet, despite Austria having no say in the matter. Joseph Stalin II starts secretly funding Communist rebels in Japan. NATO erupts into chaos as the propaganda makes people far overly paranoid.
Finland and bordering parts of Norway are secretly annexed on 12th August 1965. NATO learns of this and threatens the declaration of World War III.
Chaos in NATO (The Red Scare) and the Japanese Rebellion
NATO was in a state of emergency of the highest tier. With the fall of West Germany and the propagandized rebels NATO was bordering on collapsing, Police and even military had to try to keep the masses under control. In Japan however something a little more sinister is occurring. Japanese Communist Rebels funded by the UCA and China (In this timeline the PRC managed to annex Taiwan and Mongolia along with the mainland and also still have decent relations with the UCA) are starting to rebel in major Japanese cities. On the 20th January 1966 the People's Republic of Japan (PRJ) is established. South Korea is silently, swiftly and very secretly annexed by North Korean forces. There is no Vietnam war like in our timeline as Vietnam becomes peacefully independent from France as a Primitive Monarchy.
An era of (tense) peace for Nations (The Cold War)
From 1967 through to 1982 not much was happening. In NATO people (gradually over the course of a few years) calm down enough to stop Rebelling. This era is known as the Cold War as the Communist and Capitalist nations do not go directly to war but instead fuel Proxy Wars (a new term) in places such as Afghanistan and Persia (many atrocities occur during the Persian Civil War however).
The Anglo Federation is officially formed on June 12th 1979 for defensive and stability reasons, although NATO still exists.