Libyan no-fly zone would be risky, provocative

After days of unrest in Libya, U.S. officials say a no-fly zone is an option for pushing Moammar Gadhafi from power and preventing bloodshed in toppling the regime.

But the use of no-fly zones is rife with danger for both sides, foreign experts say, and instituting one in Libya would raise the geopolitical stakes.

A no-fly zone is the aerial equivalent of a line in the sand. Violators, whether they are civilian aircraft or fighter jets, can get shot at.

A member of the U.N. Security Council who spoke on background told CNN that while there has been no formal discussion of a no-fly zone, there have been informal discussions outside of meetings, and "informal planning" is going on at NATO for such a scenario.

The diplomat said that if the Security Council discovers evidence that Gadhafi is using his air forces to kill or bomb civilians, fly in mercenaries or impede humanitarian assistance, it would be prepared to consider a no-fly zone.