Chavez and his revolution are so powerful that various governments in South America, including that of Brazil, a rising world power, viewed the victory of Chavez in the October elections as a necessary condition for the continuity of regional integration.

CENTERFORSECURITYPOLICY: Some Reflections Over Speculations on Venezuela's Future

The arithmetic implies, as a necessary but not sufficient condition to spark EU growth (robust growth abroad is also needed), the euro should drop about 20% against the currencies of its trading partners.

FORBES: Europe Will Recover As The Euro Falls

The secret to success is to not accept this complexity as a permanent condition or a necessary evil.

FORBES: Are Your Acquisitions Creating Complexity?

That is a necessary but not a sufficient condition, as the type of rock involved, called carbonaceous chondrite, is found in other asteroids, too.

ECONOMIST: Asteroid impacts