this is how i would make mw3.
in the prologue you retake the role of mactavish. he is badly wounded but since it is only a video there isn't an effect on the players actions.
Nikolai fly's them to southern Russia where a rebel anti-ultranationalist group are trying to overthrow the current goverment and create peace. these are the loyalists from COD4.
soon after landing at there base mactavish faints and captain price's voice telling him to "hang on" faintly dies before the opening credits kick in.
the game takes place 1 year after mw2. due to the victory in America shadow company still exists and is now, due to other nations joining in the war, a multi national ask force designed with capturing or killing the traitors of the 141.
the main character is "four-leaf" jackson a british ex-SAS operative who was signed up for shadow compny to bring back the 141 or the black knights as they have become with the coalition with the loyalists.
they get a tip off from a spy in the Russian camp that the black knights are preparing to leave for china. so shadow company attacks the base.
four leaf is the first in the camp but doesnot kill any black knights. he presses on until he finds price. he has killed 3 members of shadow company but gets disamred by four leaf and placed under arreset he attempts to escape which forces four leaf to attempt to kill him but as he fires his side arm soap knocks him out cold.
after heavy fighting between the two it seems the black knights can't hold out for much longer and are almost defeated. four leaf wakes to have soap stood by him. soap instantly reconises his old friend from the SAS and spares him. he tells him "everything you have been told is a lie."
shadow company break in and try to capture both price and soap alive. they knock price to the floor and his colt m1911 .45 slides out towards four leaf. he picks it up and shoots the men which makes the black knighs allow him to escape with the two.
niklai has brought his pavelow round to pick up any stragglers but as they almost escape the new commader of shadow company arrives and threatens that if the two captains do not surender and give back four leaf then he will have soaps daughter captured and price's wife killed.
the two contemplate on surrendering an give four leaf to them he gets closer to the general and raises the colt and shoots him dead. a firefight breaks out which allows the black knights including four leaf to escape