Financial markets shuddered Monday as fears over Europe's sovereign debt crisis resurfaced yet again. Still, the Dow closed off its worst levels of the session amid the conventional view that Greece's debt crisis can be managed.

But Endgame author John Mauldin says Greece won't be any more "contained" than subprime mortgages were in 2008.

"It's not something that stops at the European waters," Mauldin says. "Just like the subprime crisis didn't stop in California…I'm worried this one has a lot of contagion and it'll affect the world."

As for the mechanism for that contagion, Mauldin lays out the following scenario in the event of a Greek default:

• - Greece has to nationalize its banks.

• - Greek citizens are forced to take deposits in drachmas, rather than euros.

• - Greek consumers and businesses then default on all debts because of the resulting haircut, which he estimates at 50%.

• - French and German banks are forced to take write-downs on their Greek exposure.

• - The ECB is forced to take a write-down on its exposure to Greek debt.

Such a scenario would not go unnoticed in Portugal or, especially, Ireland, where voters have already shown their displeasure with having to pay for bank bailouts, Mauldin notes.

Meanwhile, U.S. banks have written credit-default swaps to European banks. Most of these positions are hedged but "you're only balanced as long as both of those counterparties are good," Mauldin says. "If you have a bad counterparty, now you're out of balance."

If you'll recall, it wasn't the failing subprime mortgages per se that caused the real crisis in 2008, but banks refusal to trade with other banks. It was this "counterparty risk" which caused the financial system to seize up, which is why policymakers here and in Europe are doing everything and anything to prevent a repeat.

Aaron Task is the host of The Daily Ticker. You can follow him on Twitter at @atask or email him at altask@yahoo.com