Will playing Mass Effect multiplayer from one account affect every profile on the console?

My husband and I are using one Xbox 360, but different profiles. I want to play multiplayer in Mass Effect 3, but the Xbox Live account belongs to my husband.

The only thing I want from the multiplayer is to increase my Effective Military Strength in the single player game, but I'm not sure if it will affect the game on my profile if I use his account.