The world markets rebounded in a huge way today when the European Union unveiled a nearly $1 trillion bailout for Greece, Spain, and Portugal -- and any other European nation that may be skidding into default these days. But is it a matter of throwing good money after bad?

Motley Fool Global Gains Advisor Tim Hanson says the size and scope of this package -- which will allow traditionally stable countries like Germany and France to borrow money at low rates so they can turn around and loan it out to their withering neighbors -- makes the U.S. TARP bank-rescue fund look like chump-change in comparison. Sure, it's good news today, and international investors should be cheered that outfits like Telefonica (NYSE: TEF), National Bank of Greece (NYSE: NBG) and Portugal Telecom (NYSE: PT) exploded with the announcement, but there may be a cloud inside this silver casing.

Over time, says Hanson, the inextricable linkage of Europe's strongest and weakest economies might well drag down the lot. And it certainly calls into question the long-term viability of the euro as a currency investment. Watch the video here: