What does John 18:12 mean?

The "band of soldiers" mentioned here is part of the Roman military, authorized for this purpose. They've been led to a private place by Judas (John 18:1–3), who has turned traitor against His former Master (John 11:57; 13:2–3; Matthew 26:14–16; Luke 22:47–48). When confronted, Jesus did not run or struggle. Despite showing divine power (John 18:4–9) and Peter's demonstrated willingness to fight (John 18:10–11), Christ is not interested in battle. On the contrary, this is the purpose for which He was born (John 18:37). This is part of the plan God has sent Him to complete (Matthew 16:21).

As in other portions of this Gospel, John uses the term "the Jews" in reference to Jewish religious leadership. This is primarily composed of the scribes, Pharisees, and Sadducees (Matthew 21:15; 23:1–3). Jerusalem's ruling class considered Jesus a threat, to their status (John 11:48), their national security (John 11:50), and their reputation (John 12:42–43).

This passage further shows the effects of John writing long after the Gospels of Matthew, Mark, and Luke were in circulation. The encounter with Annas (John 18:13) and certain details about Pilate are found here, the other details are left to be covered by the other writings.