It's got to stop.
In Georgia he invaded on a flimsy pretext and attacked a constitutional, democratic government, grabbing territory and installing massive, menacing military capability in Abkhazia & South Ossetia.
In the north Caucasus he props up the nasty little regime of Ramzan Kadyrov and has foreigners skiing on the graves of Circassians killed in a 19th century genocide.
He is trying to destabilise Moldova and derail its European accession plans by generating discontent among the Gagauz, by having his Transnistrian puppet make mischief, and apparently by trying to bribe members of the pro-Europe governing coalition to switch sides.
In Syria, he is arming and defending the regime of Bashar al-Assad, creating and feeding the bogeyman of Al-Qaeda to deflect the West from taking more decisive action against the mad and genocidal Syrian government.
Now in Ukraine, he pays Yanushenko 2 billion euros, who then begins a bloody, Tienanmen-style crackdown on the pro-civilisation protesters in the Maidan, possibly initiating a civil war that will have terrible consequences for the region as a whole.
The international community needs to realise (and quickly) that Russia has started a new cold war. Unlike the first cold war, this one is not declared. Unlike the first cold war, the West has few defences in place, having been lulled into a false sense of security. Unlike the first cold war, there is no stale-mate along an iron curtain, but instead a series of creeping advances by Putin's forces (be they military, diplomatic or economic).
The tendency of western leaders is to avoid conflict and seek peaceful, negotiated outcomes. While laudable, that is what Putin is counting on. Take a mile, then surrender a few inches to appease international opinion. Then take another mile, cede a few inches. Then repeat, again and again.
Putin needs to be stopped. He needs to be publicly humiliated so that the Russian people will see him for what he is. Losing Ukraine to the civilised World would do the trick, I think.