How strong can I reasonably expect a thin wall to be?

I'm designing a custom enclosure for a diy Pi-based laptop. No matter how I design it, some thin walls will need to be printed in the weakest direction, with layers going perpendicular to the surface. I've been trying to print a wall 2mm thick, and I'm very disappointed with strength of layer adhesion - the layers separate quite easily under finger pressure on the side of the wall, not to mention what happens if I try to pull on it in both directions. I'd like to ask for advice from more seasoned printing wizards: Is this an issue with my print settings/setup, or my design (walls that are simply too thin)? How strong can I reasonably expect a 2mm wall to be?

I'm using a Prusa/Anet clone, printing in ABS without enclosure, 250 degrees C on my hot end and 75 C on the bed. 0,4mm nozzle, 0,2mm layer thickness. 100% infill, sliced with Cura and fed through Repetier.

Edit: Just printed the same part in PLA, and tried to maul it with pliers, without success. I guess I really could use an enclosure for ABS printing... But my question still stands: How to tell if what I'm printing is as durable as it can get, if I'm squeezing all the durable-juice i can get from my print?

Quality abs is very strong and rigid. I print abs all the time, within an enclosure heated to 50C. I just printed caps to cover 1/4" threaded rod ends that have 2 .4mm walls and they are very strong. I have never printed abs over 235C and my bed is normally 110C I also have made larger boxes with PETG and a .75mm nozzle (.8mm single walls) that are very robust . I also tap threads in abs parts with no issues, do it all the time.
Things that need to be right are initial Z offset (starting height) as the hotter the bed the more it will change so make sure you verify it is correct. Drop temp to 235C as well
Tiny cap is ABS other parts are PETG with .75 nozzle