Crimea isn't exactly a massive conquest, nor did it take much in the way of resources to pull the peninsula back into the Russian orbit. But already, Russia is reporting the economic indigestion that tends to follow an imperialist meal. The expenses and uncertainties involved in biting off a piece of another country rattled investors and sent money elsewhere. That might not have mattered if Russia was a wealthy country that could afford the luxury of bullying its neigbors. But it's not, and so Putin and company are discovering very quickly that belligerence tends to come with sanctions more effective than the ones politicians prattle about.
According to Darya Korsunskaya at Reuters:
In February Russia's gross domestic product eked out growth of just 0.3 percent year-on-year, down from 0.7 percent in January, Russia's Deputy Economy Minister Andrei Klepach said.
Last year the economy grew by just 1.3 percent, far below initial forecasts, but there had been hopes that growth would rebound this year. Instead Russia's economic performance is deteriorating further as the international tensions around Ukraine lead capital to flee Russia. …
While Russia's economic growth slows, inflation is shooting up. The Economy Ministry expects inflation to reach 6.9-7.0 percent in March, up from 6.2 percent in February.
The sharp rise illustrates how a slumping rouble is feeding into higher import prices, as both Russians and foreigners scramble to get out of rouble investments.
Note that this has little to do with formal sanctions, according to reports. Bureaucratic penalties, to the extent they work at all, don't function with the speed of scared investors getting their money the hell out.
Empire probably doesn't have to be universally ruinous to the conqueror. There may be a temporary upside if you're Roman or medieval Spanish about it and just suck the conquests dry while worrying little about economic ties with people who see peaceful, predictable environments as the best hosts for their business efforts. That might work, for a bit.
But that's not the modern world. In a piece for The Atlantic advocating for an American Empire, Robert D, Kaplan concedes, "the real problem with imperialism is not that it is evil, but rather that it is too expensive and therefore a problematic grand strategy for a country like the United States. Many an empire has collapsed because of the burden of conquest."
Russia won't collapse over Crimea. But it will gag over the tab for a while.