In DAIM USA I made the AI build less ships, especially in the early years, and made it build more land divisions instead (but less garrisons). I tried to focus the research more on the interesting parts - although almost everything can be interesting for the US.
Apart from that there are a couple of other tweaks and changes. Expect a US AI that has significantly more divisions and is using them to make invasions - sometimes more, sometimes less, I got the impression the number of invasions by the AI is linked to the weather outside... 
Downloads:
Instructions/Notes:
Downloads:
Instructions/Notes:
- if you only want to play with the modification for the USA AI, download the first and the second link and extract the two files into your HoI 2 directory (first the framework, then the AI, you'll have to confirm overwriting a few files)
- you can use any of the six other DAIM sets (Germany, Italy, Japan, NatChina, Soviet Union, United Kingdom) on top of the framework if you like
- if you want to play with all seven available DAIM sets, you can also use the third download link - extract the file into your HoI 2 directory
- if you want to revert to the original 1.1 files, use the ai_backup.zip in the same way (last link)
- the mod works with the 1936 and 1939 scenarios
- only AI files and necessary switch events are changed/added, there are no artificial handicaps for the player - feel free to apply higher difficulty settings at the same time
- ever since Europa Universalis 1, reloading from time to time seems to help the AI to do its job, I recommend reloading about once a year.