"This is a political issue overlooked by many people," the infamously pessimistic economist told CNBC on Monday. "If Greece leaves, the North Atlantic Treaty Organization [NATO] countries led by America are very afraid that Russia will establish
closer relationships [in the Mediterranean]."
Many economists agree that if Athens does default on its multi-billion dollar debt repayments, $840 million of which is due Tuesday to the International Monetary Fund (IMF), the chances of a Grexit, i.e. Greece leaving the euro currency bloc, are high.
But, should that occur, "the Russian fleet can move into the Mediterranean from the Black Sea," Faber said.
Russia's occupation of Crimea and east Ukraine in the Black Sea makes an entry into the Mediterranean very possible due to the Black Sea's close proximity, Faber explained, adding that a Grexit essentially provides Putin the perfect opportunity to do so.
Greece is generally regarded as a gateway to the Mediterranean, it is also a key NATO outpost in the Balkans.
Faber's theory is underscored by European worries of closer ties between Athens and Moscow following Greek Prime Minister Alexis Tsipras' visit to Russia in April.
"It is clear that Tsipras is allowing Putin to drive a wedge between European countries concerning their stance on Russia," British think tank Civitas said in a note last month.
The European Union has reason to be concerned over relations between Greece and Russia, said Dimitrios Triantaphyllou, associate professor at Istanbul's Kadir Has University. "Zbigniew Brzezinski's [former U.S. national security adviser] recent comments in an interview that should Greece come closer to Russia, it could paralyze NATO, should serve as a warning of the dire consequences," he wrote in a blog post last month.
While strategists may disagree with Faber's theory, Moscow's rising political clout in European peripheral nations is raising concerns. Nomura believes domestic socioeconomic stresses in Russia will likely see President Putin ramp up his foreign expansion plans outside of Crimea and east Ukraine.
"We expect Russian provocations to continue, including in NATO territory, short of an outright land grab," said Alastair Newton, the bank's senior political analyst, in a March report.
"The recent launch of military exercises involving disputed territories such as Crimea, Abkhazia and South Ossetia is an indicator of this, sending further warning signs to neighbors and the West alike."