Liberation is another scenario that's encountered fairly often in this campaign, but it can be a downright nightmare depending on the map.
It's a classic 2v1 scenario, expect that if your Ally gets eliminated, you get eliminated as well. The enemy starts with a larger army than you, and will often rush one of you, aiming to put you out of the game.
This is the hardest part of the scenario and once you pass it, the rest of it will be easier (unless it's the Liberation scenario featuring North Korea, then you will get no relaxation).
Aim to grab the science, civic and military technologies in that order. You'll want to build a city quickly and then either a temple or bunker at your capital, in case you are attacked. Send your army to defend your ally, who has basically nothing.
In this scenario, I was attacked (wrong choice), so with a temple and my army coming back to help me, it's easier to manage the assault. The Russians, having stronger attrition damage also make it easier to hold out. Afterwards, definitely add a bunker to buy time for when further assaults happen.
After this, it's a 2v1, your enemy will keep attacking, so keep defending as you and your ally both build your economy. If they attack you, defend as your ally will usually threaten their cities and force them to retreat. if they attack your ally, defend them and keep building your economy. Eventually, both you and your ally will overpower the enemy and it'll be game over for them.
TIPS:
- Forced march and entrenching your units will help move and defend your units better
- Whenever the enemy attacks, you want to buy time. Bunkers help do this, or you can eliminate enemy tanks or bazooka units as they do the most damage. If they attack you, build a temple as that adds 50% more health to a city. As the Russians, you get attrition upgrades for free so add in a bunker as soon as possible. Building 5 different buildings in a city makes the city a large city, giving it more health.
- Defend and attack with your ally. There is strength in numbers!