Thieves are special Allied operatives tasked with breaking into enemy refineries and silos to reroute the funds (half of the building's resource pool to be precise). They appear in Red Alert 1.
Lacking the resources to face the Soviets in direct combat, the Allies began to resort to covert operations along with guerilla warfare. Pressed for resources and time, the Allied army decided to hire professional thieves to disrupt the Soviet economy.
Thieves are unarmed and wear cloaks with hats. They rely on their stealth and speed to succeed in their assignments.
Several were deployed alongside Tanya Adams during the final assault on Moscow.
The secretly Allied-aligned Molotov Brothers also used thieves, they were also fond of placing a couple in APCs to steal resources from the player.
Being unarmed, thieves are very vulnerable on the battlefield and easily killed. Unlike spies, they can't cloak either, so the player has to rely on his skills in distraction to allow a thief to enter the target building. If he manages it, then half of the credits are routed into the player's credit pool.
Thieves' field renders somehow bear resemblances to Zorro or Tuxedo Mask.