Raptor -
See this link for deep background -
http://simhq.com/forum/ubbthreads.php/topics/3610212/DCS_Mission_Building_Discussio.html#Post3610212Deactivating a Group will take it off of the battlefield, and that will also classify the Group as Dead (in v1.1.1.1 anyway). If you want to make the unit act up on a trigger, set up a Triggered Actions for the Group at Waypoint SP or another as appropriate to do Alarm State = Red.
But what I think you want is to have the Red group 'reappear' every time Blue units come around. If that's the case then you need to Copy/Paste the Group multiple times and Deactivate the first, Activate the second, Deactivate second Activate third, etc.
Or, use Triggered Action Invisible. Make your group appear and disappear to the enemy this way. I think Invisible hides the Group even in Fog Of War (?).
I have had varying success with Clients tripping the triggers, BTW. Test test test.
Wrecking Crew