This command will add stability (max. 100%). You can remove stability by specifying a negative number.
Note that in order to change the stability of another country you will first need to switch using the tag command, and then execute the st command to add or remove stability.
st [amount]
| Amount | The percentage of stability you wish to add. Maximum stability % is 100. |
st 35
Executing the above command would add 35% stability
st -10
This cheat would remove 10% stability from your current country, as negative 10 (-10) has been specified.