> I wonder what you think Putin's endgame might be
I don't think Putin has a unidimensional, monolithic "endgame". What I think he has is a recognition of his vulnerabilities and his strengths and priorities he wishes to advance in light of those so that he remains in power and is not murdered in his sleep, or by other means.
The strengths exist on various levels. Internationally, Russia is the natural ally of all enemies of the United States. Iran, North Korea, Venezuela, and the like all come to mind. This is less because of differences in the people (Russians and Americans are very much alike in nearly every way that matters), but with the political histories and traditions of the two countries. Russia is an old world country with a history of invasion from the Kievan Rus to the Second World War. Nationally, Russia is a country that has almost no historical, cultural, or other institutional memory of what it means to live in a democracy. Top-down rule has always been the rule, and that did not change from the Tsar Nicholas II, to Stalin, to Gorbachev, to Putin. Yeltsin was the only variation, and that lasted less than a decade. Putin is a new Tsar, and the people understand that democracy is little more than a rouse to trick the rest of the world into thinking that Russia is more Western than it is. Historically, insofar as Russia has always been ruled by a monarch or a despot, the people -- regardless of their actual thoughts -- do not rebel, or at least they haven't done so meaningfully since there was almost a color revolution in Moscow in 2014.
The weaknesses exist on the same levels. Internationally, Russia's standing in the world has fallen precipitously. It's allies are falling and its client states (namely, Iran and Syria) are either in ruin or were working towards peace with the United States -- which means the end of alliances with Russia. Iran has a nuclear deal. North Korea isn't de-nuclearizing, but they have no value to Putin. Venezuela is not a diplomatic asset but a liability as civil war resulting from economic instability beckons an American style foreign imposed regime change, or a Gaddafi style uprising against Maduro. Personally, I'm rooting for the latter. As Putin knows, if Maduro is out, then Putin is more likely to face a color revolution of his own. These things do not happen in a vacuum, and Putin knows this. That is why he has threatened intervention as he has. The same applies to Assad in Syria. Nationally, the Russian economy is in crisis; there is a rampant HIV/AIDS epidemic resulting from drug use and shared needles; Russians abuse drugs and alcohol at higher and higher rates; unemployment is at record highs; economic opportunity is almost nonexistent above slave wages. Indeed, there are many Russians whose material conditions were better under the USSR than under Putin.
Domestically, however, Putin faces the additional challenge of preventing popular uprising while enriching the class of oligarchs his regime has minted. This presents problems, because consumption is conspicuous and Russia is failing economically for working Russians. The reason is obvious: enriching oligarchs, which is only accomplished by stealing from the state, means that the same money leaves Russia and never returns. It hides in secret bank accounts in Cyprus, the Isle of Mann, Gibraltar, Panama, and other jurisdictions that do not comply with the United States' and EU's reporting requirements. It is unclear how much longer this can continue. But, there is also the derivative problem of ensuring that his oligarch's wealth is not frozen from Western financial institutions, as happened under Obama. Where sanctions of the sort entered by the Obama administration become the new norm, Putin's utility to those same oligarchs diminishes.
So, this is the "hand" Putin's holding... or a brief preview of it at least.
I'll say some things about how he'll play it and how he is playing it in a subsequent post.