Russia's economy is in deep trouble. Crippled by sanctions and stung by slumping oil prices, the nation's currency has lost half its value against the US dollar since June.

"Because of the volatility of the rouble, many foreign businesses are finding it impossible to operate in Russia, and they have either scaled back their operations or actually closed," financial risk analyst and author Satyajit Das said.

Just this week, technology giant Apple stopped selling its products online into Russia because it could not keep up with the rouble's rapid decline.

However, the Russian crisis could extend far beyond its borders, and foreign companies that make or sell goods there.

"Russia is a big debtor to foreign banks and to foreign investors, and also it's a major trading partner to Europe," Mr Das added.

He told ABC News Online that the GFC should remain a firm reminder of how quickly, widely and unexpectedly financial problems can spread.

"One of the things that 2008 reinforced is that, in a globalised economy, trade and capital flows link sometimes very disparate economies and if something goes wrong in one part of the world it can very, very quickly affect other parts of the world," he noted.

Some of these links can be surprising.

One example is Russia's holding of Australian dollars as part of its currency reserves - reserves which the Russian central bank has been selling off in large amounts in a vain attempt to stabilise the rouble.

"When its reserves are collapsing, then clearly the Aussie is one of the currencies that will be sold," said Westpac senior currency strategist Sean Callow.

That is one factor helping to explain the Australian dollar's recent slide below 82 US cents.

Although that in itself is not necessarily a bad thing.

""It's fall has been pretty relentless, but it hasn't been too sudden," Mr Callow added.

"It may fall below 80 [US cents] soon but that's desirable, particularly if its in an environment when its falling fairly modestly. Exporters have been crying out for help for a number of years and now they're finally getting some."

Oil price slump

Aside from the crippling effect of sanctions imposed by many Western nations in response to Russian intervention in Ukraine, the main factor driving the rouble lower has been a slump in oil prices.

Like the rouble, the benchmark West Texas crude price has roughly halved from around $US107 a barrel in June to just over $US54 today.

This trigger of the rouble crisis is also bad news for other energy exporters, including Australia.

"We're a net oil importer, but we're a net energy exporter, so a fall in energy prices overall does tend to weigh on the trade outlook," said Mr Callow.

Australia has embarked on a massive expansion of its liquefied natural gas (LNG) industry, relying on massive exports to Asia to pay for the cost of construction and generate profits.

Sorry, this audio has expired Ex-banker Satyajit Das warns the Russian crisis could spread

However, Mr Das said those profit margins are looking increasingly shaky for many projects as LNG prices gradually track oil prices lower.

"Those projects need somewhere between $US12 and 14 in terms of LNG price to work - LNG prices are now at $US9," he observed.

Many projects are protected by long-term contracts, but there will be pressure to renegotiate those deals if energy prices remain at these levels or lower longer term.

While crippling Russia, and threatening other energy exporters, many analysts say the slump in oil prices may provide an economic boost to the majority of nations that import oil and gas.

"Europe is a net importer of energy, people might say well there is going to be a bit of quantitative greasing coming into the economy from the lower oil prices, so maybe we can hold off on the quantitative easing part of the equation," said Satyajit Das.

However, Mr Das added that there is no guarantee that this will happen.

"The actual assumption underlying all of this is that the people who are getting this benefit will spend ... if consumers receive this so-called windfall, if they spend it that would be net positive, but if they just use it to pay off debt or save it in other ways it won't be positive," he said.

Mr Das has also warned that there is an ever bigger global threat lurking across the world's financial markets, and it is one created by the major central banks.

"Roughly 50-60 per cent of all growth since 2009 has been actually created by the loose money policies, similarly, using some measures, roughly 80 per cent of the increase in equity prices can be attributed to the same factor," he noted.

"The world now needs about $200-250 billion of liquidity pumped into the global economy every quarter just to maintain things as they are."

With the Federal Reserve having turned recently off its money printing tap, 2015 will be a telling year to see how global financial markets and economies survive an eventual rise in US interest rates.