WASHINGTON—Putting the nation on alert against what it has described as a “highly credible terrorist threat,” the FBI announced today that it has uncovered a plot by members of al-Qaeda to sit back and enjoy themselves while the United States collapses of its own accord.

“We have intercepted electronic communication indicating that al-Qaeda members are actively plotting to stay out of the way while America as we know it gradually crumbles under the weight of its own self-inflicted debt and disrepair,” FBI Deputy Director Mark F. Giuliano told the assembled press corps. “If this plan succeeds, it will leave behind a nation with a completely dysfunctional economy, collapsing infrastructure, and a catastrophic health crisis afflicting millions across the nation. We want to emphasize that this danger is very real.”