This is the source of most confusion. There was a game called Call of Duty: Modern Warfare 3: Defiance .
Call of Duty: Modern Warfare 3 was initially released in 2011 for PC, Xbox 360, and PlayStation 3. The game's massive success led to a high demand for a portable version, which was subsequently released for the PSP. The PSP version, although toned down in terms of graphics and gameplay, still managed to deliver an exhilarating experience for gamers on-the-go. The game's engaging storyline, coupled with its fast-paced multiplayer mode, made it an instant hit among PSP owners.
The official 2011 Modern Warfare 3 was released on PS3, Xbox 360, PC, and Nintendo Wii. The PSP did receive a Call of Duty game, but it was titled Call of Duty: Roads to Victory Why You Can't Find an "Official" MW3 PSP ISO Hardware Limitations:
