A proximity detonation is preferred over a direct hit in surface to air missile defense against hostile aircraft.3
The rationale behind designing anti-aircraft, surface to air missiles, for proximity detonations is simple. The initial rationale for proximity was a narrow miss in the early days. As accuracy and dependability improved, proximity fuses were often kept, in addition to impact fuse, as it had been discovered an aircraft's air-frame can actually contain the effect of the explosive warhead, depending on the design of the aircraft and the location of impact. A modern missile guided to proximity detonation (a mere few feet away from the aircraft) is likely to inflict greater damage, more often than not, because the shrapnel from the high explosive warhead has a better chance at penetrating and damaging a wider area of the target, more readily compromising critical flight control systems (especially wing-flaps and associated hydraulics.) This is why light mobile combat systems such as the Russian Strela 10's early and middle models (through 1988) with a three kilo warhead had both impact and proximity fuses. The Strela, proximity fused three kilogram warhead used by Iraq in Desert Storm (1991) was capable of taking down the American A-10 'Warthog' (two A-10s shot down by this missile, according to the American military), one of the toughest planes to shoot down with ground-fire in modern combat (to this day).4
By the era of the Stinger, very effective against Soviet helicopters in Afghanistan, missiles had become so maneuverable and accurate, the Stinger was only adapted for a proximity fuse in later (recent) development phases; to be effective against very small (difficult to direct hit) UAVs (drones.) The three kilo (average) warhead launched with a MANPAD (shoulder launched) surface to air missile, it was likely a Stinger FIM-92J (proximity fused warhead), provided by CIA to the so-called 'moderate opposition', is what had brought down a SU-25 in Syria:
Comment: See also: