Modern Warfare 2, the sequel to Call of Duty 4: Modern Warfare, is in development and set to release on November 10, 2009. It was officially announced by Activision Blizzard on December 3, 2008.

No co-operative play will be included in the campaign of Modern Warfare 2, unlike the previous installment. In the Game Informer article, Infinity Ward stated that co-op campaign detracted greatly from the cinematic effect of the game no matter how they tried to implement it. However, a new mode of gameplay, called Special Forces mode, will include co-operative play. Special Forces mode will include several fast-paced action missions similar to Mile High Club which will be of much higher difficulty than normal campaign missions and will lack real stories.

It has also been stated that NPCs will carry customized weaponry, similar to multiplayer.

In at least one mission, enemy soldiers will be amongst non-combatant civilians, forcing the player to discern between civilians and militia soldiers.

Modern Warfare 2 is to feature Russia once again in political turmoil. Makarov, a political leader coming from the shadow of Imran Zakhaev, plots to cause a chain of events that would threaten global security. The plan made by Makarov is deemed dangerous enough for Task Force 141, led by Cpt. Soap MacTavish, to be deployed to Russia. There, the force must fight its way through near-white out conditions. After escaping the scene on snowmobiles, Task Force 141 is later deployed to Rio De Janeiro to capture an arms der linked to the plot, eventually being led to the barren lands of Afghanistan. But the intel Cpt. Soap MacTavish and the rest of Task Force 141 is receiving is likely inaccurate, as even they do not understand the danger of the sinister plot.

On May 10th, a promotional video for Modern Warfare 2 was unveiled on TNT. Multiple weapons were shown in the video, all of which are listed above, along with weapons shown in the Game Informer article. On May 21st, a second promotional video was shown on GTTV. Both of the two videos were pieces of the large trailer that was to be released on May 24th, to which an Infinity Ward developer responded, "The extended trailer which launches on ModernWarfare2.com on Sunday will be 5x the amount of content.".[3]

Sure enough, the full length trailer topped off at around 2 minutes with more gameplay than was previously shown. The trailer's debut was so popular that the official Infinity Ward forums were crashed for nearly ten minutes, due to the flood of people.