The present standoff in Ukraine makes me think of two things. First, in 1994 Ukraine voluntarily gave up its control of Soviet nuclear weapons then stationed on its territory under American pressure. Kiev wanted to please Washington, which wanted only one nuclear successor state for the Soviet Union rather than four (Belarus and Kazakhstan were the other two republics with nuclear weapons). For the sake of the nuclear non-proliferation regime, Washington wanted Moscow to assume complete control of all Soviet nuclear weapons. I remember thinking that given Russian history, Ukraine was crazy to give up control of its deterrent to Moscow--the capital that had twice in the past strangled Ukrainian sovereignty. Had I been an adviser in the Clinton administration I would have urged Clinton not to pressure any of the three republics to give up their weapons for a few years until Moscow had proved its good intentions.
The other thought is that the situation in 1991-92 in the former Soviet Union as the Soviet Empire collapsed was very similar to the situation in Ireland in 1921 as British control of Ireland collapsed. Britain partitioned Ireland in two creating a Northern Ireland and a Southern Ireland. As part of the peace treaty that ended the Irish War of Independence in December 1921, the unionists who were a majority of the population in Northern Ireland were given the option of opting out of the Irish Free State by petitioning the King to remain part of the United Kingdom. This meant that the nationalists could claim that Northern Ireland had seceded from the Free State while the six Ulster counties that made up the new province of Northern Ireland never experienced Irish rule since the union of Great Britain and Ireland in 1801. When Northern Ireland was created by partition in the summer of 1921 in preparation for a settlement in the South, it was created in order to maximize the amount of territory that the unionists could rule without fear of losing control to an Irish majority. Traditionally Ulster has consisted of nine counties: the six that made up Northern Ireland in the east and center of the province and Co. Cavan and Co. Monaghan to the south and Co. Donegal to the west. The two westernmost counties in Northern Ireland, Fermanagh and Tyrone had always had a majority nationalist (Irish) population, but in 1921 the margin between the nationalist majority and unionist minority was only about five percent. It is now claimed that nationalists are a majority in four of the six counties (all but Co. Down and Co. Antrim) of Northern Ireland due to a higher birthrate and greater emigration by Protestants to Britain.
Had Yeltsin demanded, he would have been in a good position to redraw the borders of Russia to reflect areas in the republics that were predominantly ethnic Russian such as in eastern Ukraine and the Crimean peninsula and mostly in the eastern part of the three Baltic States. In the Baltic States it would have been more problematic as Lithuania, Latvia, and Estonia had all been independent countries until 1940 when Stalin invaded and annexed them under cover of World War II and the Molotov-Ribbentrop Pact. Vilna, Riga, and Tallinn would have objected and Washington would have supported them. I think these two issues worked against each other. Yeltsin had to promise to respect the independence and territorial integrity of Ukraine, Belarus, and Kazakhstan in order to get all the Soviet nuclear weapons back. Had this not been the case, he might have been able to redraw some of Russia's borders to better reflect demographic realities as London had done in Ireland during decolonization. This is clearly an instance where nuclear weapons worked against the interests of a country having them.