If vig do not decay on non contacted regions then Troop Transfer is in question . They will go to max vig. and lock more and more Strength.
Super Add Troop Strength is controlled by Global Vigilance
Creates two Alert (Strength) points in its region and one in each of two adjacent regions.
Requires 20+ excess global vigilance. Can target a region that is already receiving a regular Add Troop Strength mission.
So in one move you can get +4 Str and they will move if not locked if you add Add Troop Strength this is +3 for just one region.
Spike vigilance more and you will get another +4 all over the place after cooldown .
From Wiki
Regional Vigilance decays automatically by 1 point every 7 days, so if a region is empty of any XCOM activity it will eventually return on a less alarmed status.
Low Global vigilance play is fast Avatar project.
Build Research Facility - Requires Alert (Strenght?) >= Vigilance.
http://ufopaedia.org/index.php/Advent%27s_Agenda_(LW2)
Threat is Global Vigilance
*********************Severe (20 to 30)
At Severe and above, the aliens gain access to a "Super Reinforcements" activity which creates twice as many Alert points.
TODO: Does this replace the normal reinforcement activity or does it allow two reinforcements at once?
We forgot this mission Add Force Level - One in the world, 16 day cooldown. Always in the safest alien region (uncontacted, if possible).
You should have more than one uncontacted high strength region on late map with all
Add Troop Strength - Creates one Alert point in its region and one in a random adjacent region.
And
Super Add Troop Strength - just check your Threat level