Here are the slides of William's talk on 'Multi-Unit Planning with HTN and A*' at the 2009 AIGameDev.com's Paris game AI conference. The talk explains how a HTN planner using A* can create coordinated combined-arms attack and defense plans for a multi-unit task force.
This attack and defense planning is part of PlannedAssault, a web-based mission generator creating large scale combined-arms battles for the ArmedAssault (aka ArmA) game by Bohemia Interactive (but isn't any way endorsed or affiliated by Bohemia Interactive). PlannedAssault currently is in closed beta. PlannedAssault is both a demonstration vehicle for some AI research and a small contribution to a great community of ArmedAssault add-on and mod creators.