If you are staring at a Cyrillic menu, hearing a German commander, or navigating a Polish pause screen, take heart: The solution is out there. It lives on a dusty forum thread from 2012, preserved by a user named "ViciousPoultry." It is 1.8GB of pure nostalgia.
If your version of Modern Warfare 3 isn't set to English by default, or if you've accidentally changed it to another language, downloading an English language pack can help. This is particularly useful for: Download Modern Warfare 3 English Language Pack