In the classical world, punitive raiding served a simple purpose:
shock and awe. Raiding forces -- advancing by foot, horse, or boat --
laid waste to enemy villages and cities and captured or killed those
responsible for defying state power. By demonstrating the steep
consequences of opposing the state, the raider established a crude form
of deterrence and exercised influence far beyond its otherwise limited
means. It didn't hurt that raiding forces -- like the Roman legion --
were often qualitatively superior to their victims.
Even so, states utilizing raiding have found it difficult to achieve
lasting security. Unless incorporated into a sound long-term
political-military strategy, raiding has only ever been a temporary
solution to long-term problems. Many expeditions, while tactically
devastating, did not compel obedience or deterrence. The British colonial experience
in the 19th century is instructive, with many inconclusive operations
in Africa and South Asia that did little to enhance the Empire's
long-term security on the periphery. Some missions, like the First
Anglo-Afghan War in the 19th century, were outright blunders of epic
proportions.
The problem wasn't that raiding forces couldn't shock and awe
barbarians. But tactical raiding operations have not been enough on
their own to deal with the overarching strategic problems they mean to
solve. Historian Edward Luttwak notes
that Rome eventually shifted to garrisoning its periphery, a
distribution of forces that deprived the Empire of enough forces to
deter its opponents.
The purpose of raids had changed since the time
of the Roman and British empires, but their method, and underlying
weakness as a strategy, have remained surprisingly consistent. Now,
instead of creating deterrence through devastation, modern raiding aims
to achieve carefully targeted policy objectives: for example, the
capture or killing of high-value targets, the destruction of critical
enemy infrastructure, or the rescue of hostages. Instead of large
columns of expeditionary forces, raiding increasingly utilizes small,
forward-deployed special operations forces (SOF) capable of nearly
superhuman endurance. The political sensitivity of these discretionary
operations and the ability to micromanage them through modern
communications in turn necessitates direct executive control.
Raiding tactics have also shifted from overwhelming force to
relative superiority. SOF forces are lightly armed and numerically
inferior to the opposition, using surprise, planning, quick execution,
and the practice that comes with detailed rehearsals, and lightning
speed to gain a decisive advantage early in the mission. As William
McRaven wrote in his Naval Postgraduate School thesis
15 years before he would go on to lead the bin Laden mission, even the
tightest enemy defense network cannot always remain at full alert
everywhere -- allowing space for a small force to exploit a gap in
readiness.