Cuban Defector Exposes Hole in U.S. Air Defense : Military: MIG flies undetected to Key West, Fla. Officials say system is geared to other threats, and such lapses probably can’t be stopped.

MIAMI —  The undetected flight of a Soviet-built MIG from Cuba to Key West, Fla., exposed gaps in the nation’s southern air defense that military officials say may be all but impossible to plug.

The March 20 incident has prompted an internal investigation by NORAD, the U.S.-Canadian command charged with protecting North American airspace, spokesman Maj. John Niemann said.

No interceptors were scrambled to meet the MIG-23 flown by a defecting Cuban pilot, and tower personnel in Key West were unaware of the warplane’s approach until it had circled the island several times attempting to land.

In 1969, another Cuban defector flew a MIG all the way to Homestead Air Force Base, just south of Miami, where it landed.

NORAD blames the lapses in part on a policy that since the 1960s has fixated on the Soviet Union.

“We are aware of the gaps in our coverage,” Niemann said. “For years our emphasis was toward the (North) Pole and toward the coasts, and then when ICBM’s (intercontinental ballistic missiles) came in, even that air defense system was allowed to atrophy.”

Radar and other detection systems along the southern border have been beefed up since 1989 to combat drug trafficking.

NORAD’s explanation doesn’t sit well with some military experts. Retired Rear Adm. Gene La Roque, who heads the Washington-based Center for Defense Information, said: “For me, it’s incomprehensible that NORAD can’t pick a MIG up, coming in from Cuba. Are we wasting our money for an air defense system that doesn’t work?”

But former Assistant Secretary of Defense Lawrence J. Korb said the key issue is not an unexpected flight by a defector, but rather how the system would react to a full-scale military attack.