Here is the full list of all 34 Battle Group 2 achievements.
Fight off the Talon's submarine
Earn 10 stars
Unlock an upgrade
Unlock a support ship
Watch the airliner fly away
Fend off The Talon once more
Use all 3 Satelite Strikes
Use all 3 Satelite Strikes 10 times each
Reload 3 secondaries with one Reload
Take down 15 missiles with one EMP
Unlock a new primary ship
Unlock 4 primary ships
Unock 4 support ships
Unlock 8 ships in total
Fire 10,000 missiles
Hit 1,000 targets
Hit 10,000 targets
Earn 20 stars
Earn 30 stars
Fire 1,000 missiles
Earn 50 stars
Earn 80 stars
Destroy 500 Frogfoot planes
Destroy 1,000 Frogfot planes
Destroy 500 Skyhawk planes
Destroy 500 Flanker planes
Destroy 500 Hind helicopters
Destroy 1,000 Hind helicopters
Destroy 500 Cruise Missiles
Destroy 500 Suicide Boghammers
Destroy 1,000 Suicide Boghammers
Destroy 1,000 Skyhawk planes
Destroy 1,000 Flanker planes
Destroy 1,000 Cruise Missiles