A meeting of European Union finance ministers Sunday failed to ease fears that Greece would default on its debt. The EU put off releasing the first chunk of a $155 billion aid package until mid-July, by which time Greek leaders must pass an austerity program. The news dragged down stocks in Europe and unnerved investors in the U.S. How could Americans be affected by Greece's debt crisis? Here, three theories:

1. Your safest investments could be at risk
Even "plain-vanilla investment accounts in the U.S. could be challenged if Greece defaults on its sovereign debt," says John Carney at The Christian Science Monitor. That's because U.S. money market funds have lent $360 billion to European banks that have, in turn, made massive loans to Greece. About 12 percent of the money in those U.S. funds is tied up in loans to the French banks — Crédit Agricole, BNP Paribas, and Société Générale — who are Greece's main lenders.

2. Mortgage rates could sink
Investors nervous about putting their money into European banks are looking for safe places to put their funds, and one of the safest is U.S. Treasury bonds," says Liz Freeman at ShopRate. As demand rises, the government can get people to snap up the bonds at lower and lower interest rates, and that "should help drive down the rates on mortgages" in the U.S.

3. More Americans may lose jobs
If Greece can't pass the austerity measures, which slash government jobs and benefits, it won't get more foreign aid, and it will default on its $165 billion debt this summer. That would scare investors from buying government bonds from other European countries, sparking crises in other debt-laden countries, such as Ireland and Portugal, and then even pushing bigger economies, such as Spain and Italy, to the brink. Of course, if all goes well, a Greek bailout will prevent that catastrophe. But either way, our important European trading partners "will have less money to spend on American goods, causing job losses here," says Michael Murray at ABC News.

Sources: Wall St. Journal, NY Times, Shoprate.com, Christian Science Monitor, NPR, ABC News