Below i will show how to probably get it running idk.
Note: This may or may not help, its an Infinity Ward product, and their games are hilariously badly made


- MAKE SURE YOU HAVE SPEC OPS INSTALLED ALONGSIDE THE CAMPAIGN

This was a bug since launch of the steam version, and it is what it is, just cope honestly, because incompetent dev team.

Now that you know about the spec ops funny.

- GO TO THE SETTINGS>GRAPHICS>QUALITY AND SET THESE 2 OPTIONS TO THE LOWEST QUALITY

I, uh, i dont know why this makes it fixed, but it does.

- RESTART SHADER INSTALLATION

After that you can change the settings to high again.

With all of that, you should be able to commit war crimes in this game. I hope this helps, because idk what else would. Have a baller time, gentlemen.