Command & Conquer: Red Alert 2 Tips

Battle Lab Infiltration
Using a spy (or a mind-controlled spy if you are the soviets), you can infiltrate opponent battle labs. If you infiltrate an Allied Battle Lab, you are given Chrono Commando if you have an Allied Barracks. If you capture or own a Soviet Barracks, you can also create Chrono Ivan. If you infiltrate a Soviet Battle lab, you can create PSI Commando using the Allied Barracks
and Yuri Prime for Soviet Barracks.

PS: To get Chrono Ivan or Yuri Prime, you will need to capture or own a barracks of the opposite team to be able to train them. Also, unless you have a cloning vat, you can only create one Yuri Prime.