The key to this global economic system was the importance placed on commercial activities by Islamic merchants.

ECONOMIST: The once and future boom

The agencies were set up solely to help Americans get cheaper mortgages, but they've become key parts of the global economic system.

NPR: U.S.-China Cash Flow Depends On Fannie, Freddie

And Europe is our largest trading partner and a key part of the global financial system, and therefore it's very important to the United States, and the rest of the world as they work through their issues.

WHITEHOUSE: Press Briefing