Higly specialized, a barely armoed tankette with a short ranged flamethrower. When playing GBR, you will often be outnumbered in terms of fielded infantry, as your troops are much better trained, but should the enemy infantry count get out of hand, there is an easy solution to your problems. Since it is considered armored, the WASP cannot be damaged by rifle fire - only AT rifles and grenades can damaged it, as well as anything big enough to do damage to armor in general. It's short ranged makes it a bit risky to use often, but any infantry caught in the fire are garanteed to burn to their deaths, alloing a well controlled Wasp to take out several squads in a few seconds.
As fire does huge damage to buildings, it can be used as a cheap raider unit later on. As long as nothing fires at it in this stage, you will probably take down a yard or two without much trouble. Storages will probably destroy the Wasp in the explosion, though, but still worth it.