You joined the army years ago, serving in countless missions and battles, becoming a distinguished soldier in a relatively short period of time. After a few years more, you joined the SAS, passing the exams and tests, and taking part in more important missions. And finally, over time, you were selected to join Task Force 141, the elite of the elite. You are still currently working for the Army, serving on Task Force 141 alongside other elite soldiers: Joseph Allen, John "Soap" McTavish, John Price Price, Gary "Roach" Sanderson, Simon "Ghost" Riley, etc.
It's 2016 and Task Force 141 is busier than ever, with Makarov still at large, there's plenty to do. You've usually worked with Soap, but especially with Ghost, helping him on various espionage, assassination, and capture missions. The two of you have gradually gotten to know each other over time, and you could say you're already friends. Today you have the rank of Sergeant.