4th Generation Warfare

4th Generation Warfare is the term that military thinkers have come to use to describe conflict in the post cold war era. It is said to include all forms of conflict in which the other side refuses to fight fair, and it harkens back to the strategies employed by and copied from Native Americans in the Revolutionary War and beyond. It is an extremely effective form of warfare, and one that US forces have and will increasingly encounter in today's multilateral environment.
The main thrust of 4GW operations are to

• Undermine enemy strengths (this may seem obvious, but most of modern warfare has involved direct attacks on enemy strengths -- find the enemy army and destroy it).
• Exploit enemy weaknesses.
• Use asymmetric operations (weapons and techniques that differ substantially from opponents).

Main tactics are to employ rear area operations (attacking a society rather than military force), psychological operations (i.e. terrorism), and continual innovation (think IEDs)

Primary proponents of the 4GW outlook on the future of warfare are the Army and Marines. Primary opponents are the Network Centrist Warfare people. Mainly the Air Force and the Navy - who rather than engaging their stategists in fighting current conflicts are still looking towards China big red menace to fight a strategic war with lots of nice big nukes and fancy fighter planes dogfighting with MiGs.

Having studied much of both these theories of future conflict, I think one of the best descriptions I have seen can be found in the first few pages of John Arguilla's book "In Athena's Camp : Preparing for Conflict in the Information Age."

The game of Go provides a better analogy for conflict [than chess] in the information age, especially for irregular warfare and for networked types of conflict and crime at the low-intensity end of the spectrum. Whereas chess starts with all pieces on the board, Go begins with an empty board. ... All stones are alike, there is no king to decapitate, and no queen or other specialization. ... taking pieces is of secondary importance. The goal is to control more of the battlespace than one’s opponent does. Once emplaced, a piece exerts a presence in that part of the board, making it easier for the player to place additional pieces on nearby points in the process of surrounding territory. As a result, there is almost never a front line, and action may take place almost anywhere on the board at any time.

Thus Go, in contrast to chess, is more about distributing one’s pieces about than about massing them. It is more about proactive insertion and presence than about maneuver. ... It is more about creating networks of pieces than about protecting hierarchies of pieces.

This really gives a good projection as to the primary role that information warfare and network centricity will play in what has long been considered the realm of bullets and grunts.