The Marine Corps will begin its leadership transition in Afghanistan’s northern Helmand province soon, with Regimental Combat Team 8, out of Camp Lejeune, N.C., replacing Lejeune’s RCT-2, Marine officials said. The RCT-8 deployment will begin this weekend with advanced parties of Marines deploying. They’ll eventually replace RCT-2. For those who lead RCT-8, the assignment won’t be an easy one. It oversees some of the most violent territory that Marines patrol right now, including the contested Taliban stronghold of Sangin. Infantry battalions under RCT-8’s control will include 3rd Battalion, 5th Marines, out of Camp Pendleton, Calif.; elements of 3rd Battalion, 25th…