Those types of cards were creating money-laundering schemes, and they were trying to put an end to it.
Signed into law by President Obama on May 22, 2009, the Credit CARD Act contains the toughest credit card regulations in the history of the industry. Provisions of the law were phased in over about a 15-month period.
The first provisions began in August 2009 and included giving consumers at least 45 days advance warning of significant changes to their accounts.
There are other cards available that can make overseas purchases though, it's just Visa cards were mainly the culprit of money-laundering.
To get the actual details, you'll have to dig into the CFR's.