The Lightning Bug program had proven highly successful. A series of fast-track adaptations of an existing target drone resulted in a system whose effectiveness was beyond expectations, even with guidance technology that was extremely crude by 21st century standards. Despite this, Lightning Bugs could not affect the course of the war. Drone reconnaissance clearly showed that the North Vietnamese were violating their agreement with the Americans on a massive scale, but the U.S. leadership was unwilling to commit to ending its "endless war". When the North Vietnamese began their last offensive in early 1975 the U.S. did little to stop it; Saigon fell on April 30, 1975 and the war was over.