"Darcheha darchai noam, V'chol nesivoseha shalom"
"Milchamta shel torah". "Lo nahir lo bahir velo zahir" (Hasagas HaRaavad). "Rischa D'oraisa"
. I once saw a Chasam Sofer that says the reason why Talmidei Chachamim marbim shalom baolam, is bec. a certain amount of Milchamah is gepaskent on Rosh Hashanah, and Talmidei Chachamim with their Milchamta shel torah, take away from the amount of milchamah the Umos engage in.