So here's the promised summary of what's known about the dissolution of the USSR. As I've mentioned some of this is fairly nebulous and there are a lot of details to eventually be discovered that may change some stuff here... but with that aside, here:
Abkhazia
Inter-ethnic fighting between Abkhaz and Georgians begins 16/7/89. Abkhaz boycott Georgian independence referendum of 31/3/91, declaration of independence from Georgia 23/7/91. Georgian forces quickly occupied the capital Sukhumi, after which Abkhaz government began receiving support from Circassia, Chechnya, and Turkey... tripartite peace treaty between Abkhazia, Ossetia, Georgia signed 31/12/93. Joined CIS 1/3/95, CISFTA signatory
Armenia
Declaration of state sovereignty inside USSR 23/8/90, independence declared 21/9/91, recognised 26/12/91. Founding member of CIS 21/12/91, CISFTA signatory.
Azerbaijan
Declaration of state sovereignty inside USSR 23/9/89, independence declared 18/10/91, recognised 26/12/91. Founding member of CIS 21/12/91, not CISFTA signatory.
Belarus
Declaration of state sovereignty inside USSR 27/7/90, independence declared 25/8/91, recognised 26/12/91. Founding member of CIS 21/12/91, CISFTA signatory.
Chechnya
Declaration of state sovereignty of the Checheno-Ingush ASSR inside USSR 26/11/90, independence declared 1/11/91 with peaceful split into Chechnya and Ingushetia simultaneously... Russia refused recognition as Checheno-Ingush ASSR had not been a constituent member of the USSR but part of RSFSR... Budyonnovsk hospital incident led to signing of ceasefire 18/6/95; independence recognised 17/10/95 (Caucasus Agreement). Refused to join CIS.
Circassia
Independence declared ?/?/?, recognised 17/10/95 (Caucasus Agreement). Refused to join CIS.
Dagestan
Independence declared ?/?/?, recognised 17/10/95 (Caucasus Agreement). Joined CIS 22/6/99, not CISFTA signatory.
Estonia
Declaration of state sovereignty inside USSR 16/11/88, independence declared 8/5/90, recognised 6/9/91. Refused to join CIS... joined Nordic Union 10/2/92, joined NATO 29/3/04
Georgia
Declaration of state sovereignty inside USSR 26/5/90, independence referendum 31/3/91, independence declared 9/4/91, recognised 26/12/91. Ossetia-Georgia War starts 5/1/91... coup against first President Zviad Gamsakhurdia 22/12/91 supported by Russia, Gamsakhurdia receives assistance from Chechnya and Circassia ... tripartite peace treaty between Abkhazia, Ossetia, Georgia signed 31/12/93. Joined CIS 19/4/94, CISFTA signatory.
Idel-Ural
Bashkortostan, Chuvashia, Mari El, Mordovia, Tatarstan, and Udmurtia all declared independence from RF on 15/3/91, immediately unifying to create Idel-Ural. Yugra declares independence from RF 29/4/91. Komi ASSR, Komi-Permyak AO, Perm Oblast declare independence 11/5/91 and merge to form Komi Republic... 17/5/91 Idel-Ural War between IE and RF begins... 24/5/91 fire exchanged between Yugran security forces and Russian forces stationed there... Yamalia declares independence 28/5/91... Yugra joins Idel-Ural 1/6/91... Nenetsia declares independence 27/6/91... Yamalia and Nenetsia join Idel-Ural 27/7/91... 17/9/91 ethnic rebellions (i.e. attacks against Slavs) in Yekaterinburg (now Tsybartora) and rest of Sverdlovsk Oblast, mostly Tatars and Bashkirs, lead to declaration of intention to join Idel-Ural, Sverdlovsk Oblast joins Idel-Ural 20/4/92... war... 23/12/93 ceasefire, 17/6/94 Treaty of Athens signed between Russia and Idel-Ural. Refused to join CIS.
Ingushetia
Declaration of state sovereignty of the Checheno-Ingush ASSR inside USSR 26/11/90, independence declared 1/11/91 with peaceful split into Chechnya and Ingushetia simultaneously... Russia refused recognition as Checheno-Ingush ASSR had not been a constituent member of the USSR but part of RSFSR... Budyonnovsk hospital incident led to signing of ceasefire 18/6/95; independence recognised 17/10/95 (Caucasus Agreement). Joined CIS 12/8/2010, CISFTA signatory.
Kalmykia
Independence declaration ?/?/?, recognised 17/10/95 (Caucasus Agreement). Joined CIS 12/6/96, not CISFTA signatory.
Karelia
Declaration of state sovereignty inside USSR 7/4/90, independence declared 21/8/90, recognised 14/6/92. Refused to join CIS, joined Nordic Union 5/9/92.
Kazakhstan
Declaration of state sovereignty inside USSR 25/10/90, independence declared 16/12/91, recognised 26/12/91. Was the last SSR to declare independence. Founding member of CIS 21/12/91, CISFTA signatory.
Kyrgyzstan
Declaration of state sovereignty inside USSR 15/12/90, independence declared 31/8/91, recognised 26/12/91. Founding member of CIS 21/12/91, CISFTA signatory 1/14
Latvia
Declaration of state sovereignty inside USSR 28/7/89, independence declared 4/5/90, recognised 6/9/91. Refused to join CIS... joined Central European Community 4/12/00, joined NATO 29/3/04
Lithuania
Declaration of state sovereignty inside USSR 26/5/89, independence declared 11/3/90, recognised 6/9/91. Refused to join CIS... joined Central European Community 4/12/00, joined NATO 29/3/04...
Moldova
Declaration of state sovereignty inside USSR 23/6/90, independence declared 27/8/91, recognised 26/12/91. Refused to join CIS. Referendum on joining Romania 26/5/92 passed with 81% voting in favour; Romanian referendum on accepting Moldova 3/10/93 passed with 72% voting in favour; official merger of Romania and Moldova 1/1/95.
Ossetia
Petition to Supreme Soviet of the USSR for creation of Ossetian SSR submitted 10/11/89, South Ossetia declaration of independence from Georgia 20/9/90... 5/1/91 National Guard of Georgia enters Tskhinvali and fighting breaks out between NGG and Ossetian police... Ossetia supported by Chechnya, Circassia, and Turkey; Georgia supported by Russia, North Ossetia declaration of independence from Russia 18/3/91... declaration of unified Ossetian state 1/5/91... tripartite peace treaty between Abkhazia, Ossetia, Georgia signed 31/12/93 ... merger with North Ossetia recognised by Russia 17/10/95 (Caucasus Agreement). Joined CIS/CISFTA 24/11/11
Primoria
All-Union Referendum of 17/3/91 which although passed, reinforced an east/west divide of opinion within the RSFSR... this further divided as tensions in the Caucasus increased, eastern opinion being largely in favour of granting independence. Outbreak of Checheno-Ingush war led to large demonstrations in cities around the Soviet Far East... led to 22/12/91 joint declaration of heads of Amur, Magadan, Kamchatka, and Sakhalin Oblasts, Primorsky Kray, and the Buryat ASSR of opposition to the Moscow government = interpreted as declaration of independence... first fighting broke out between Moscow loyalists concentrated in Zabaykalsky Kray and Primorsky Kray (i.e. military bases including the Vladivostok naval base) 24-28/12/91 ... some naval skirmishes in Sea of Okhotsk... heavier fighting happens in eastern Krasnoyarsk Kray (Russia) particularly around Irkutsk; front stabilises by summer 1992, combat becomes mostly artillery exchanges and airstrikes - Primorian forces begin a slow advance into Krasnoyarsk Kray as Russia focussing on Caucasus and Idel-Ural... 19 April 1993 ceasefire, peace treaty recognising Primorian independence signed 10 June 1993, Krasnoyarsk Kray returned to Russia. Primoria refuses to join CIS.
Prussia
Population mostly Russian, however opportunism led to independence declaration 24/4/90, name of Kaliningrad restored to Königsberg 29/4/90... independence recognised 22/1/92, Russian Navy retains right to use of naval base at Pillau (formerly Baltiysk) for ten years... by 10/7/93 all Russified placenames had been restored to their previous names (pre-1938 names, in most cases where the name had also been changed in 1938 in the Nazis' Germanification campaign of the late 1930s)... last Imperial Russian Air Force units withdraw from Insterburg Air Base 17/8/95, withdrawal of Russian ground forces complete by 23/9/95, Navy withdrawal from Pillau complete 21/1/02... Prussia joined NATO 29/3/04... refused to join CIS, joined European Union 2010.
Tajikistan
Declaration of state sovereignty inside USSR 22/8/90, independence declared 27/10/91, recognised 26/12/91. Founding member of CIS 21/12/91, CISFTA signatory 12/15.
Turkmenistan
Declaration of state sovereignty inside USSR 22/8/90, independence declared 27/10/91, recognised 26/12/91. Signed CIS foundation treaty but never ratified, therefore not a member.
Tuva
Independence declaration ?/?/?, recognised 23/6/94. Refused to join CIS.
Ukraine
Declaration of state sovereignty inside USSR 16/7/90, independence declared 24/8/91, recognised 26/12/91. Founding member of CIS 21/12/91, CISFTA signatory
Uzbekistan
Declaration of state sovereignty inside USSR 20/6/90, independence declared 1/9/91, recognised 26/12/91. Founding member of CIS 21/12/91, not CISFTA signatory
Yakutia
Declaration of independence 14/2/92, recognised 23/5/94. Refused to join CIS.
Russia
All of the above relevant, plus...
Declaration of state sovereignty inside USSR 12/6/90, Russian Federation established 12/12/91, recognised dissolution of the USSR 26/12/91 ... second coup in Moscow 15/5/93 successful - undertaken by Restorationist factions of the military supported by the Orthodox Church, Russsian ethnonationalists, and other anti-Socialist groups... restoration of the monarchy proclaimed 12/12/93, RF renamed Соединённое русское царство (= "United Russian Tsardom", colloquially "Russian Empire") as a federal parliamentary constitutional monarchy... new government sought immediately to bring Caucasian and eastern wars to an end...
CIS = 1994 Framework for Bilateral Free Trade Agreements and Freedom of Transit
CISFTA = 2011 Multilateral Free Trade Area Treaty 18/10/11
There have been major population movements since the various independences. Many - but by no means all - Russians have left the various new states; conversely almost all ethnic minorities who were inside Russia and whose ethnicity was represented in one of the new states (Tatars for example) have left Russia.
