Zugzwang is a German word: When playing chess you are in the situation that you have to make a move, but any move puts you in a worse position.
This is Putin's problem: After his success with Crimea when the Kiev Government were in disarray he though putting a few GRU officers and terrorists to seize buildings in Donetsk and Luhansk regions would trigger a popular uprising with a rigged vote to join Russia, Ie. the same as he had done in Crimea. His miscalculation is that only a very small number of Ukrainians and ethnic Russians are interested in joining Russia where most people in the region put a greater value on personal freedom, reducing corruption and making more money by having closer ties with the rich part of Europe, the EU, than being under the thumb of dictator Putin.
At home Putin annexing Crimea has made him very popular and so he has done a big propaganda sell with a nationalist policy about rebuilding a new Russian empire, part of this is the new Russian province 'Novorussia' by annexing all of the South and East of Ukraine. He is using nationalism to paper over the cracks that are appearing in their economy. He is not the first to do this by any means, Galtieri did the same by invading the Falklands and when he lost he was deposed.
Now the Ukrainian army have got their act together and have recovered much of the territory seized by the Russian terrorists and to try and stop total defeat Putin and Russia are being drawn deeper and deeper into the conflict. They are still shipping much heavy military equipment over the border to support the terrorists and have escalated further by firing Grad rockets from Russia at Ukrainian troops and shot down from over the Russian some Ukrainian aircraft flying in Ukraine airspace. They have now moved Grad launchers temporarily into Ukraine to stop Donetsk being cut off by the Ukrainian Army's latest drive. This he may have got away with as the west (with the exception of Canada) had little interest in the fate of Ukraine and were content to have a few token sanctions to show their disapproval, but MH17 has changed all of that.
Now if he is defeated in Ukraine or ends up with a poor political settlement he will take a hard knock on the home front, which could involve him being deposed, if he continues to escalate his support for the terrorists in Ukraine the west have made it quite clear the will add more sanctions, which will add to his economic problems and to the restrictions on his inner circle and he may well end up being deposed. Unless he finds away out of this, he needs to make sure Russia goes short on piano wire and avoid lampposts.
Sanctions have meant the Russian central Bank since Crimea has raised their Base rate from 5.5% to 8% defending the value of the Rouble. They have also spent substantial currency reserves on doing the same. Companies that have been borrowing from Western financial institutions are finding it much more difficult to refinance and interest rates are higher. The problem companies have is not only the current sanctions, but also banks don't want to be left holding non-tradeable debt if sanctions increase further. Putin can't retaliate against the west with an energy war as that would crash his economy, where 45% of his economy depends on oil and gas sales most of it to Western Europe. The EU, US, Canada, Japan and other OSCE countries have a combined GDP of $35tn against Russia's $2tn they can afford to take the small losses from sanctions compared to Russia.
Maybe he should take this Ukrainian graffiti on Donbass military chief Strelkov as good advice.