Strike Legion: Platoon Leader

From the publisher's website:

Strike Legion: Platoon Leader is a 15mm-based small unit combat game, where individual soldiers can make the difference between victory and defeat. The game features:

Alternating squad-based activations, with each team of a squad capable of carrying out independent actions
Team actions that allow great latitude in tabletop operations, including a sensible Overwatch system and multiple team actions per turn based on morale status
Leaders and leadership actions that affect teams, squads, and (possibly) the actions of your entire force
Special rules for crew, medic, scout, and sniper teams
Crewed weapons and squad support weapons
A section dedicated to special characters (Personalities)
Complete vehicle combat rules, including provisions for gunships and infantry teams mounted on personal vehicles
Several dozen infantry team attributes, weapons characteristics, and vehicle systems that can be incorporated into the player's own unit designs using the enclosed unit construction rules
Seven scenarios and over two dozen pre-made units
Simple conversion scales to use figures ranging from 6mm to 28mm, based individually or with figures mounted on team bases.

While its focus is on futuristic combat, Strike Legion: Platoon Leader can easily be used to fight platoon- and company-level actions from World War II through modern settings with minimal modifications to the rules.